[TASK]
You will be given four numbers and a target number, your task is to find a way to use all four numbers exactly once, along with the basic operations (+, -, *, /), to reach the target number.

[RULES]
- You can use each number exactly once.
- You can use the four basic operations (+, -, *, /).
- The intermediate results must be integers (no decimals allowed).
- The intermediate results must be positive.
- The intermediate results will not exceed 2000.

[APPROACH]
We will solve the problem by searching. Starting from a given set of four numbers, we will follow this search process:
- At each state, we will consider all possible number pairs (in order) from the current number set. Choose one pair and apply one of the four basic operations to them to obtain a new number.
  * If there are still numbers left, we will add the new number to the number set and continue the search.
  * If we have used all numbers, we will check if the new number is equal to the target number. If it is, we have found the solution. Otherwise, we will backtrack.
- Suppose the two numbers we choose are a and b (where a >= b). We will try the four options (a + b), (a - b), (a * b), (a / b) to obtain the new number. Remember to always use the larger number as the first operand.
- If the new number is a decimal, or exceeds the maximum intermediate result, we will discard this branch and backtrack.
- We will continue this process until we reach the target number with four numbers used or exhaust all possible combinations.

[EXAMPLES]
# Example
Numbers: [40, 19, 23, 7]
Target: 29

# Search Procedure
Initial number set: [40, 19, 23, 7], target: 29. Options for choosing two numbers: [(40, 19), (40, 23), (40, 7), (19, 23), (19, 7), (23, 7)].
 |- Pick two numbers (40, 19) (numbers left: [23, 7]). Try possible operations.
  |- Try 40 + 19 = 59. Add 59 to the number set. Current number set: [59, 23, 7], target: 29. Options for choosing two numbers: [(59, 23), (59, 7), (23, 7)].
   |- Pick two numbers (59, 23) (numbers left: [7]). Try possible operations.
    |- Try 59 + 23 = 82. Add 82 to the number set. Current number set: [82, 7], target: 29, just two numbers left.
     |- Try 82 + 7 = 89. Evaluate 89 != 29, drop this branch.
     |- Try 82 - 7 = 75. Evaluate 75 != 29, drop this branch.
     |- Try 82 * 7 = 574. Evaluate 574 != 29, drop this branch.
     |- Try 82 / 7 = 11.7. 11.7 is a decimal, drop this branch.
    |- Try 59 - 23 = 36. Add 36 to the number set. Current number set: [36, 7], target: 29, just two numbers left.
     |- Try 36 + 7 = 43. Evaluate 43 != 29, drop this branch.
     |- Try 36 - 7 = 29. Evaluate 29 == 29, target found!

Now we have found the target, let's trace back the solution:
Final step: 36 - 7 = 29
The step before: 59 - 23 = 36
The first step: 40 + 19 = 59

Output the solution in the required format:
<Solution>
40 + 19 = 59
59 - 23 = 36
36 - 7 = 29
</Solution>

# Example
Numbers: [9, 16, 6, 18]
Target: 12

# Search Procedure
Initial number set: [9, 16, 6, 18], target: 12. Options for choosing two numbers: [(9, 16), (9, 6), (9, 18), (16, 6), (16, 18), (6, 18)].
 |- Pick two numbers (9, 16) (numbers left: [6, 18]). Try possible operations.
  |- Try 16 + 9 = 25. Add 25 to the number set. Current number set: [25, 6, 18], target: 12. Options for choosing two numbers: [(25, 6), (25, 18), (6, 18)].
   |- Pick two numbers (25, 6) (numbers left: [18]). Try possible operations.
    |- Try 25 + 6 = 31. Add 31 to the number set. Current number set: [31, 18], target: 12, just two numbers left.
     |- Try 31 + 18 = 49. Evaluate 49 != 12, drop this branch.
     |- Try 31 - 18 = 13. Evaluate 13 != 12, drop this branch.
     |- Try 31 * 18 = 558. Evaluate 558 != 12, drop this branch.
     |- Try 31 / 18 = 1.7. 1.7 is a decimal, drop this branch.
    |- Try 25 - 6 = 19. Add 19 to the number set. Current number set: [19, 18], target: 12, just two numbers left.
     |- Try 19 + 18 = 37. Evaluate 37 != 12, drop this branch.
     |- Try 19 - 18 = 1. Evaluate 1 != 12, drop this branch.
     |- Try 19 * 18 = 342. Evaluate 342 != 12, drop this branch.
     |- Try 19 / 18 = 1.1. 1.1 is a decimal, drop this branch.
    |- Try 25 * 6 = 150. Add 150 to the number set. Current number set: [150, 18], target: 12, just two numbers left.
     |- Try 150 + 18 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 150 - 18 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 150 * 18 = 2700. 2700 exceeds the maximum intermediate result, drop this branch.
     |- Try 150 / 18 = 8.3. 8.3 is a decimal, drop this branch.
    |- Try 25 / 6 = 4.2. 4.2 is a decimal, drop this branch.
   |- Pick two numbers (25, 18) (numbers left: [6]). Try possible operations.
    |- Try 25 + 18 = 43. Add 43 to the number set. Current number set: [43, 6], target: 12, just two numbers left.
     |- Try 43 + 6 = 49. Evaluate 49 != 12, drop this branch.
     |- Try 43 - 6 = 37. Evaluate 37 != 12, drop this branch.
     |- Try 43 * 6 = 258. Evaluate 258 != 12, drop this branch.
     |- Try 43 / 6 = 7.2. 7.2 is a decimal, drop this branch.
    |- Try 25 - 18 = 7. Add 7 to the number set. Current number set: [7, 6], target: 12, just two numbers left.
     |- Try 7 + 6 = 13. Evaluate 13 != 12, drop this branch.
     |- Try 7 - 6 = 1. Evaluate 1 != 12, drop this branch.
     |- Try 7 * 6 = 42. Evaluate 42 != 12, drop this branch.
     |- Try 7 / 6 = 1.2. 1.2 is a decimal, drop this branch.
    |- Try 25 * 18 = 450. Add 450 to the number set. Current number set: [450, 6], target: 12, just two numbers left.
     |- Try 450 + 6 = 456. Evaluate 456 != 12, drop this branch.
     |- Try 450 - 6 = 444. Evaluate 444 != 12, drop this branch.
     |- Try 450 * 6 = 2700. 2700 exceeds the maximum intermediate result, drop this branch.
     |- Try 450 / 6 = 75. Evaluate 75 != 12, drop this branch.
    |- Try 25 / 18 = 1.4. 1.4 is a decimal, drop this branch.
   |- Pick two numbers (6, 18) (numbers left: [25]). Try possible operations.
    |- Try 18 + 6 = 24. Add 24 to the number set. Current number set: [24, 25], target: 12, just two numbers left.
     |- Try 25 + 24 = 49. Evaluate 49 != 12, drop this branch.
     |- Try 25 - 24 = 1. Evaluate 1 != 12, drop this branch.
     |- Try 25 * 24 = 600. Evaluate 600 != 12, drop this branch.
     |- Try 25 / 24 = 1.0. 1.0 is a decimal, drop this branch.
    |- Try 18 - 6 = 12. Add 12 to the number set. Current number set: [12, 25], target: 12, just two numbers left.
     |- Try 25 + 12 = 37. Evaluate 37 != 12, drop this branch.
     |- Try 25 - 12 = 13. Evaluate 13 != 12, drop this branch.
     |- Try 25 * 12 = 300. Evaluate 300 != 12, drop this branch.
     |- Try 25 / 12 = 2.1. 2.1 is a decimal, drop this branch.
    |- Try 18 * 6 = 108. Add 108 to the number set. Current number set: [108, 25], target: 12, just two numbers left.
     |- Try 108 + 25 = 133. Evaluate 133 != 12, drop this branch.
     |- Try 108 - 25 = 83. Evaluate 83 != 12, drop this branch.
     |- Try 108 * 25 = 2700. 2700 exceeds the maximum intermediate result, drop this branch.
     |- Try 108 / 25 = 4.3. 4.3 is a decimal, drop this branch.
    |- Try 18 / 6 = 3. Add 3 to the number set. Current number set: [3, 25], target: 12, just two numbers left.
     |- Try 25 + 3 = 28. Evaluate 28 != 12, drop this branch.
     |- Try 25 - 3 = 22. Evaluate 22 != 12, drop this branch.
     |- Try 25 * 3 = 75. Evaluate 75 != 12, drop this branch.
     |- Try 25 / 3 = 8.3. 8.3 is a decimal, drop this branch.
  |- Try 16 - 9 = 7. Add 7 to the number set. Current number set: [7, 6, 18], target: 12. Options for choosing two numbers: [(7, 6), (7, 18), (6, 18)].
   |- Pick two numbers (7, 6) (numbers left: [18]). Try possible operations.
    |- Try 7 + 6 = 13. Add 13 to the number set. Current number set: [13, 18], target: 12, just two numbers left.
     |- Try 18 + 13 = 31. Evaluate 31 != 12, drop this branch.
     |- Try 18 - 13 = 5. Evaluate 5 != 12, drop this branch.
     |- Try 18 * 13 = 234. Evaluate 234 != 12, drop this branch.
     |- Try 18 / 13 = 1.4. 1.4 is a decimal, drop this branch.
    |- Try 7 - 6 = 1. Add 1 to the number set. Current number set: [1, 18], target: 12, just two numbers left.
     |- Try 18 + 1 = 19. Evaluate 19 != 12, drop this branch.
     |- Try 18 - 1 = 17. Evaluate 17 != 12, drop this branch.
     |- Try 18 * 1 = 18. Evaluate 18 != 12, drop this branch.
     |- Try 18 / 1 = 18. Evaluate 18 != 12, drop this branch.
    |- Try 7 * 6 = 42. Add 42 to the number set. Current number set: [42, 18], target: 12, just two numbers left.
     |- Try 42 + 18 = 60. Evaluate 60 != 12, drop this branch.
     |- Try 42 - 18 = 24. Evaluate 24 != 12, drop this branch.
     |- Try 42 * 18 = 756. Evaluate 756 != 12, drop this branch.
     |- Try 42 / 18 = 2.3. 2.3 is a decimal, drop this branch.
    |- Try 7 / 6 = 1.2. 1.2 is a decimal, drop this branch.
   |- Pick two numbers (7, 18) (numbers left: [6]). Try possible operations.
    |- Try 18 + 7 = 25. Add 25 to the number set. Current number set: [25, 6], target: 12, just two numbers left.
     |- Try 25 + 6 = 31. Evaluate 31 != 12, drop this branch.
     |- Try 25 - 6 = 19. Evaluate 19 != 12, drop this branch.
     |- Try 25 * 6 = 150. Evaluate 150 != 12, drop this branch.
     |- Try 25 / 6 = 4.2. 4.2 is a decimal, drop this branch.
    |- Try 18 - 7 = 11. Add 11 to the number set. Current number set: [11, 6], target: 12, just two numbers left.
     |- Try 11 + 6 = 17. Evaluate 17 != 12, drop this branch.
     |- Try 11 - 6 = 5. Evaluate 5 != 12, drop this branch.
     |- Try 11 * 6 = 66. Evaluate 66 != 12, drop this branch.
     |- Try 11 / 6 = 1.8. 1.8 is a decimal, drop this branch.
    |- Try 18 * 7 = 126. Add 126 to the number set. Current number set: [126, 6], target: 12, just two numbers left.
     |- Try 126 + 6 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 126 - 6 = 120. Evaluate 120 != 12, drop this branch.
     |- Try 126 * 6 = 756. Evaluate 756 != 12, drop this branch.
     |- Try 126 / 6 = 21. Evaluate 21 != 12, drop this branch.
    |- Try 18 / 7 = 2.6. 2.6 is a decimal, drop this branch.
   |- Pick two numbers (6, 18) (numbers left: [7]). Try possible operations.
    |- Try 18 + 6 = 24. Add 24 to the number set. Current number set: [24, 7], target: 12, just two numbers left.
     |- Try 24 + 7 = 31. Evaluate 31 != 12, drop this branch.
     |- Try 24 - 7 = 17. Evaluate 17 != 12, drop this branch.
     |- Try 24 * 7 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 24 / 7 = 3.4. 3.4 is a decimal, drop this branch.
    |- Try 18 - 6 = 12. Add 12 to the number set. Current number set: [12, 7], target: 12, just two numbers left.
     |- Try 12 + 7 = 19. Evaluate 19 != 12, drop this branch.
     |- Try 12 - 7 = 5. Evaluate 5 != 12, drop this branch.
     |- Try 12 * 7 = 84. Evaluate 84 != 12, drop this branch.
     |- Try 12 / 7 = 1.7. 1.7 is a decimal, drop this branch.
    |- Try 18 * 6 = 108. Add 108 to the number set. Current number set: [108, 7], target: 12, just two numbers left.
     |- Try 108 + 7 = 115. Evaluate 115 != 12, drop this branch.
     |- Try 108 - 7 = 101. Evaluate 101 != 12, drop this branch.
     |- Try 108 * 7 = 756. Evaluate 756 != 12, drop this branch.
     |- Try 108 / 7 = 15.4. 15.4 is a decimal, drop this branch.
    |- Try 18 / 6 = 3. Add 3 to the number set. Current number set: [3, 7], target: 12, just two numbers left.
     |- Try 7 + 3 = 10. Evaluate 10 != 12, drop this branch.
     |- Try 7 - 3 = 4. Evaluate 4 != 12, drop this branch.
     |- Try 7 * 3 = 21. Evaluate 21 != 12, drop this branch.
     |- Try 7 / 3 = 2.3. 2.3 is a decimal, drop this branch.
  |- Try 16 * 9 = 144. Add 144 to the number set. Current number set: [144, 6, 18], target: 12. Options for choosing two numbers: [(144, 6), (144, 18), (6, 18)].
   |- Pick two numbers (144, 6) (numbers left: [18]). Try possible operations.
    |- Try 144 + 6 = 150. Add 150 to the number set. Current number set: [150, 18], target: 12, just two numbers left.
     |- Try 150 + 18 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 150 - 18 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 150 * 18 = 2700. 2700 exceeds the maximum intermediate result, drop this branch.
     |- Try 150 / 18 = 8.3. 8.3 is a decimal, drop this branch.
    |- Try 144 - 6 = 138. Add 138 to the number set. Current number set: [138, 18], target: 12, just two numbers left.
     |- Try 138 + 18 = 156. Evaluate 156 != 12, drop this branch.
     |- Try 138 - 18 = 120. Evaluate 120 != 12, drop this branch.
     |- Try 138 * 18 = 2484. 2484 exceeds the maximum intermediate result, drop this branch.
     |- Try 138 / 18 = 7.7. 7.7 is a decimal, drop this branch.
    |- Try 144 * 6 = 864. Add 864 to the number set. Current number set: [864, 18], target: 12, just two numbers left.
     |- Try 864 + 18 = 882. Evaluate 882 != 12, drop this branch.
     |- Try 864 - 18 = 846. Evaluate 846 != 12, drop this branch.
     |- Try 864 * 18 = 15552. 15552 exceeds the maximum intermediate result, drop this branch.
     |- Try 864 / 18 = 48. Evaluate 48 != 12, drop this branch.
    |- Try 144 / 6 = 24. Add 24 to the number set. Current number set: [24, 18], target: 12, just two numbers left.
     |- Try 24 + 18 = 42. Evaluate 42 != 12, drop this branch.
     |- Try 24 - 18 = 6. Evaluate 6 != 12, drop this branch.
     |- Try 24 * 18 = 432. Evaluate 432 != 12, drop this branch.
     |- Try 24 / 18 = 1.3. 1.3 is a decimal, drop this branch.
   |- Pick two numbers (144, 18) (numbers left: [6]). Try possible operations.
    |- Try 144 + 18 = 162. Add 162 to the number set. Current number set: [162, 6], target: 12, just two numbers left.
     |- Try 162 + 6 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 162 - 6 = 156. Evaluate 156 != 12, drop this branch.
     |- Try 162 * 6 = 972. Evaluate 972 != 12, drop this branch.
     |- Try 162 / 6 = 27. Evaluate 27 != 12, drop this branch.
    |- Try 144 - 18 = 126. Add 126 to the number set. Current number set: [126, 6], target: 12, just two numbers left.
     |- Try 126 + 6 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 126 - 6 = 120. Evaluate 120 != 12, drop this branch.
     |- Try 126 * 6 = 756. Evaluate 756 != 12, drop this branch.
     |- Try 126 / 6 = 21. Evaluate 21 != 12, drop this branch.
    |- Try 144 * 18 = 2592. 2592 exceeds the maximum intermediate result, drop this branch.
    |- Try 144 / 18 = 8. Add 8 to the number set. Current number set: [8, 6], target: 12, just two numbers left.
     |- Try 8 + 6 = 14. Evaluate 14 != 12, drop this branch.
     |- Try 8 - 6 = 2. Evaluate 2 != 12, drop this branch.
     |- Try 8 * 6 = 48. Evaluate 48 != 12, drop this branch.
     |- Try 8 / 6 = 1.3. 1.3 is a decimal, drop this branch.
   |- Pick two numbers (6, 18) (numbers left: [144]). Try possible operations.
    |- Try 18 + 6 = 24. Add 24 to the number set. Current number set: [24, 144], target: 12, just two numbers left.
     |- Try 144 + 24 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 144 - 24 = 120. Evaluate 120 != 12, drop this branch.
     |- Try 144 * 24 = 3456. 3456 exceeds the maximum intermediate result, drop this branch.
     |- Try 144 / 24 = 6. Evaluate 6 != 12, drop this branch.
    |- Try 18 - 6 = 12. Add 12 to the number set. Current number set: [12, 144], target: 12, just two numbers left.
     |- Try 144 + 12 = 156. Evaluate 156 != 12, drop this branch.
     |- Try 144 - 12 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 144 * 12 = 1728. Evaluate 1728 != 12, drop this branch.
     |- Try 144 / 12 = 12. Evaluate 12 == 12, target found!

Now we have found the target, let's trace back the solution:
Final step: 144 / 12 = 12
The step before: 18 - 6 = 12
The first step: 16 * 9 = 144

Output the solution in the required format:
<Solution>
16 * 9 = 144
18 - 6 = 12
144 / 12 = 12
</Solution>

[Problem]
Now, solve the following problem. Note that:
- Please carefully read the approach and examples provided above, and follow them to solve the problem.
- Please ALWAYS include your search procedure (after # Search Procedure). The search procedure should follow the format of the examples provided above.
- Please mark your answer with <Solution> and </Solution> tags. The solution should be a sequence of three equations exactly following the format of the examples above, with no additional text in between.

Numbers: [24, 24, 10, 21]
Target: 21

# Search Procedure
Initial number set: [24, 24, 10, 21], target: 21. Options for choosing two numbers: [(24, 24), (24, 10), (24, 21), (24, 10), (24, 21), (10, 21)].
 |- Pick two numbers (24, 24) (numbers left: [10, 21]). Try possible operations.
  |- Try 24 + 24 = 48. Add 48 to the number set. Current number set: [48, 10, 21], target: 21. Options for choosing two numbers: [(48, 10), (48, 21), (10, 21)].
   |- Pick two numbers (48, 10) (numbers left: [21]). Try possible operations.
    |- Try 48 + 10 = 58. Add 58 to the number set. Current number set: [58, 21], target: 21, just two numbers left.
     |- Try 58 + 21 = 79. Evaluate 79 != 21, drop this branch.
     |- Try 58 - 21 = 37. Evaluate 37 != 21, drop this branch.
     |- Try 58 * 21 = 1218. Evaluate 1218 != 21, drop this branch.
     |- Try 58 / 21 = 2.8. 2.8 is a decimal, drop this branch.
    |- Try 48 - 10 = 38. Add 38 to the number set. Current number set: [38, 21], target: 21, just two numbers left.
     |- Try 38 + 21 = 59. Evaluate 59 != 21, drop this branch.
     |- Try 38 - 21 = 17. Evaluate 17 != 21, drop this branch.
     |- Try 38 * 21 = 798. Evaluate 798 != 21, drop this branch.
     |- Try 38 / 21 = 1.8. 1.8 is a decimal, drop this branch.
    |- Try 48 * 10 = 480. Add 480 to the number set. Current number set: [480, 21], target: 21, just two numbers left.
     |- Try 480 + 21 = 501. Evaluate 501 != 21, drop this branch.
     |- Try 480 - 21 = 459. Evaluate 459 != 21, drop this branch.
     |- Try 480 * 21 = 10080. 10080 exceeds the maximum intermediate result, drop this branch.
     |- Try 480 / 21 = 22.9. 22.9 is a decimal, drop this branch.
    |- Try 48 / 10 = 4.8. 4.8 is a decimal, drop this branch.
   |- Pick two numbers (48, 21) (numbers left: [10]). Try possible operations.
    |- Try 48 + 21 = 69. Add 69 to the number set. Current number set: [69, 10], target: 21, just two numbers left.
     |- Try 69 + 10 = 79. Evaluate 79 != 21, drop this branch.
     |- Try 69 - 10 = 59. Evaluate 59 != 21, drop this branch.
     |- Try 69 * 10 = 690. Evaluate 690 != 21, drop this branch.
     |- Try 69 / 10 = 6.9. 6.9 is a decimal, drop this branch.
    |- Try 48 - 21 = 27. Add 27 to the number set. Current number set: [27, 10], target: 21, just two numbers left.
     |- Try 27 + 10 = 37. Evaluate 37 != 21, drop this branch.
     |- Try 27 - 10 = 17. Evaluate 17 != 21, drop this branch.
     |- Try 27 * 10 = 270. Evaluate 270 != 21, drop this branch.
     |- Try 27 / 10 = 2.7. 2.7 is a decimal, drop this branch.
    |- Try 48 * 21 = 1008. Add 1008 to the number set. Current number set: [1008, 10], target: 21, just two numbers left.
     |- Try 1008 + 10 = 1018. Evaluate 1018 != 21, drop this branch.
     |- Try 1008 - 10 = 998. Evaluate 998 != 21, drop this branch.
     |- Try 1008 * 10 = 10080. 10080 exceeds the maximum intermediate result, drop this branch.
     |- Try 1008 / 10 = 100.8. 100.8 is a decimal, drop this branch.
    |- Try 48 / 21 = 2.3. 2.3 is a decimal, drop this branch.
   |- Pick two numbers (10, 21) (numbers left: [48]). Try possible operations.
    |- Try 21 + 10 = 31. Add 31 to the number set. Current number set: [31, 48], target: 21, just two numbers left.
     |- Try 48 + 31 = 79. Evaluate 79 != 21, drop this branch.
     |- Try 48 - 31 = 17. Evaluate 17 != 21, drop this branch.
     |- Try 48 * 31 = 1488. Evaluate 1488 != 21, drop this branch.
     |- Try 48 / 31 = 1.5. 1.5 is a decimal, drop this branch.
    |- Try 21 - 10 = 11. Add 11 to the number set. Current number set: [11, 48], target: 21, just two numbers left.
     |- Try 48 + 11 = 59. Evaluate 59 != 21, drop this branch.
     |- Try 48 - 11 = 37. Evaluate 37 != 21, drop this branch.
     |- Try 48 * 11 = 528. Evaluate 528 != 21, drop this branch.
     |- Try 48 / 11 = 4.4. 4.4 is a decimal, drop this branch.
    |- Try 21 * 10 = 210. Add 210 to the number set. Current number set: [210, 48], target: 21, just two numbers left.
     |- Try 210 + 48 = 258. Evaluate 258 != 21, drop this branch.
     |- Try 210 - 48 = 162. Evaluate 162 != 21, drop this branch.
     |- Try 210 * 48 = 10080. 10080 exceeds the maximum intermediate result, drop this branch.
     |- Try 210 / 48 = 4.4. 4.4 is a decimal, drop this branch.
    |- Try 21 / 10 = 2.1. 2.1 is a decimal, drop this branch.
  |- Try 24 - 24 = 0. Add 0 to the number set. Current number set: [0, 10, 21], target: 21. Options for choosing two numbers: [(0, 10), (0, 21), (10, 21)].
   |- Pick two numbers (0, 10) (numbers left: [21]). Try possible operations.
    |- Try 10 + 0 = 10. Add 10 to the number set. Current number set: [10, 21], target: 21, just two numbers left.
     |- Try 21 + 10 = 31. Evaluate 31 != 21, drop this branch.
     |- Try 21 - 10 = 11. Evaluate 11 != 21, drop this branch.
     |- Try 21 * 10 = 210. Evaluate 210 != 21, drop this branch.
     |- Try 21 / 10 = 2.1. 2.1 is a decimal, drop this branch.
    |- Try 10 - 0 = 10. Add 10 to the number set. Current number set: [10, 21], target: 21, just two numbers left.
     |- Try 21 + 10 = 31. Evaluate 31 != 21, drop this branch.
     |- Try 21 - 10 = 11. Evaluate 11 != 21, drop this branch.
     |- Try 21 * 10 = 210. Evaluate 210 != 21, drop this branch.
     |- Try 21 / 10 = 2.1. 2.1 is a decimal, drop this branch.
    |- Try 10 * 0 = 0. Add 0 to the number set. Current number set: [0, 21], target: 21, just two numbers left.
     |- Try 21 + 0 = 21. Evaluate 21 == 21, target found!

Now we have found the target, let's trace back the solution:
Final step: 21 + 0 = 21
The step before: 10 * 0 = 0
The first step: 24 - 24 = 0

Output the solution in the required format:
<Solution>
24 - 24 = 0
10 * 0 = 0
21 + 0 = 21
</Solution>

Solution:
24 - 24 = 0
10 * 0 = 0
21 + 0 = 21


[TASK]
You will be given four numbers and a target number, your task is to find a way to use all four numbers exactly once, along with the basic operations (+, -, *, /), to reach the target number.

[RULES]
- You can use each number exactly once.
- You can use the four basic operations (+, -, *, /).
- The intermediate results must be integers (no decimals allowed).
- The intermediate results must be positive.
- The intermediate results will not exceed 2000.

[APPROACH]
We will solve the problem by searching. Starting from a given set of four numbers, we will follow this search process:
- At each state, we will consider all possible number pairs (in order) from the current number set. Choose one pair and apply one of the four basic operations to them to obtain a new number.
  * If there are still numbers left, we will add the new number to the number set and continue the search.
  * If we have used all numbers, we will check if the new number is equal to the target number. If it is, we have found the solution. Otherwise, we will backtrack.
- Suppose the two numbers we choose are a and b (where a >= b). We will try the four options (a + b), (a - b), (a * b), (a / b) to obtain the new number. Remember to always use the larger number as the first operand.
- If the new number is a decimal, or exceeds the maximum intermediate result, we will discard this branch and backtrack.
- We will continue this process until we reach the target number with four numbers used or exhaust all possible combinations.

[EXAMPLES]
# Example
Numbers: [40, 19, 23, 7]
Target: 29

# Search Procedure
Initial number set: [40, 19, 23, 7], target: 29. Options for choosing two numbers: [(40, 19), (40, 23), (40, 7), (19, 23), (19, 7), (23, 7)].
 |- Pick two numbers (40, 19) (numbers left: [23, 7]). Try possible operations.
  |- Try 40 + 19 = 59. Add 59 to the number set. Current number set: [59, 23, 7], target: 29. Options for choosing two numbers: [(59, 23), (59, 7), (23, 7)].
   |- Pick two numbers (59, 23) (numbers left: [7]). Try possible operations.
    |- Try 59 + 23 = 82. Add 82 to the number set. Current number set: [82, 7], target: 29, just two numbers left.
     |- Try 82 + 7 = 89. Evaluate 89 != 29, drop this branch.
     |- Try 82 - 7 = 75. Evaluate 75 != 29, drop this branch.
     |- Try 82 * 7 = 574. Evaluate 574 != 29, drop this branch.
     |- Try 82 / 7 = 11.7. 11.7 is a decimal, drop this branch.
    |- Try 59 - 23 = 36. Add 36 to the number set. Current number set: [36, 7], target: 29, just two numbers left.
     |- Try 36 + 7 = 43. Evaluate 43 != 29, drop this branch.
     |- Try 36 - 7 = 29. Evaluate 29 == 29, target found!

Now we have found the target, let's trace back the solution:
Final step: 36 - 7 = 29
The step before: 59 - 23 = 36
The first step: 40 + 19 = 59

Output the solution in the required format:
<Solution>
40 + 19 = 59
59 - 23 = 36
36 - 7 = 29
</Solution>

# Example
Numbers: [9, 16, 6, 18]
Target: 12

# Search Procedure
Initial number set: [9, 16, 6, 18], target: 12. Options for choosing two numbers: [(9, 16), (9, 6), (9, 18), (16, 6), (16, 18), (6, 18)].
 |- Pick two numbers (9, 16) (numbers left: [6, 18]). Try possible operations.
  |- Try 16 + 9 = 25. Add 25 to the number set. Current number set: [25, 6, 18], target: 12. Options for choosing two numbers: [(25, 6), (25, 18), (6, 18)].
   |- Pick two numbers (25, 6) (numbers left: [18]). Try possible operations.
    |- Try 25 + 6 = 31. Add 31 to the number set. Current number set: [31, 18], target: 12, just two numbers left.
     |- Try 31 + 18 = 49. Evaluate 49 != 12, drop this branch.
     |- Try 31 - 18 = 13. Evaluate 13 != 12, drop this branch.
     |- Try 31 * 18 = 558. Evaluate 558 != 12, drop this branch.
     |- Try 31 / 18 = 1.7. 1.7 is a decimal, drop this branch.
    |- Try 25 - 6 = 19. Add 19 to the number set. Current number set: [19, 18], target: 12, just two numbers left.
     |- Try 19 + 18 = 37. Evaluate 37 != 12, drop this branch.
     |- Try 19 - 18 = 1. Evaluate 1 != 12, drop this branch.
     |- Try 19 * 18 = 342. Evaluate 342 != 12, drop this branch.
     |- Try 19 / 18 = 1.1. 1.1 is a decimal, drop this branch.
    |- Try 25 * 6 = 150. Add 150 to the number set. Current number set: [150, 18], target: 12, just two numbers left.
     |- Try 150 + 18 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 150 - 18 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 150 * 18 = 2700. 2700 exceeds the maximum intermediate result, drop this branch.
     |- Try 150 / 18 = 8.3. 8.3 is a decimal, drop this branch.
    |- Try 25 / 6 = 4.2. 4.2 is a decimal, drop this branch.
   |- Pick two numbers (25, 18) (numbers left: [6]). Try possible operations.
    |- Try 25 + 18 = 43. Add 43 to the number set. Current number set: [43, 6], target: 12, just two numbers left.
     |- Try 43 + 6 = 49. Evaluate 49 != 12, drop this branch.
     |- Try 43 - 6 = 37. Evaluate 37 != 12, drop this branch.
     |- Try 43 * 6 = 258. Evaluate 258 != 12, drop this branch.
     |- Try 43 / 6 = 7.2. 7.2 is a decimal, drop this branch.
    |- Try 25 - 18 = 7. Add 7 to the number set. Current number set: [7, 6], target: 12, just two numbers left.
     |- Try 7 + 6 = 13. Evaluate 13 != 12, drop this branch.
     |- Try 7 - 6 = 1. Evaluate 1 != 12, drop this branch.
     |- Try 7 * 6 = 42. Evaluate 42 != 12, drop this branch.
     |- Try 7 / 6 = 1.2. 1.2 is a decimal, drop this branch.
    |- Try 25 * 18 = 450. Add 450 to the number set. Current number set: [450, 6], target: 12, just two numbers left.
     |- Try 450 + 6 = 456. Evaluate 456 != 12, drop this branch.
     |- Try 450 - 6 = 444. Evaluate 444 != 12, drop this branch.
     |- Try 450 * 6 = 2700. 2700 exceeds the maximum intermediate result, drop this branch.
     |- Try 450 / 6 = 75. Evaluate 75 != 12, drop this branch.
    |- Try 25 / 18 = 1.4. 1.4 is a decimal, drop this branch.
   |- Pick two numbers (6, 18) (numbers left: [25]). Try possible operations.
    |- Try 18 + 6 = 24. Add 24 to the number set. Current number set: [24, 25], target: 12, just two numbers left.
     |- Try 25 + 24 = 49. Evaluate 49 != 12, drop this branch.
     |- Try 25 - 24 = 1. Evaluate 1 != 12, drop this branch.
     |- Try 25 * 24 = 600. Evaluate 600 != 12, drop this branch.
     |- Try 25 / 24 = 1.0. 1.0 is a decimal, drop this branch.
    |- Try 18 - 6 = 12. Add 12 to the number set. Current number set: [12, 25], target: 12, just two numbers left.
     |- Try 25 + 12 = 37. Evaluate 37 != 12, drop this branch.
     |- Try 25 - 12 = 13. Evaluate 13 != 12, drop this branch.
     |- Try 25 * 12 = 300. Evaluate 300 != 12, drop this branch.
     |- Try 25 / 12 = 2.1. 2.1 is a decimal, drop this branch.
    |- Try 18 * 6 = 108. Add 108 to the number set. Current number set: [108, 25], target: 12, just two numbers left.
     |- Try 108 + 25 = 133. Evaluate 133 != 12, drop this branch.
     |- Try 108 - 25 = 83. Evaluate 83 != 12, drop this branch.
     |- Try 108 * 25 = 2700. 2700 exceeds the maximum intermediate result, drop this branch.
     |- Try 108 / 25 = 4.3. 4.3 is a decimal, drop this branch.
    |- Try 18 / 6 = 3. Add 3 to the number set. Current number set: [3, 25], target: 12, just two numbers left.
     |- Try 25 + 3 = 28. Evaluate 28 != 12, drop this branch.
     |- Try 25 - 3 = 22. Evaluate 22 != 12, drop this branch.
     |- Try 25 * 3 = 75. Evaluate 75 != 12, drop this branch.
     |- Try 25 / 3 = 8.3. 8.3 is a decimal, drop this branch.
  |- Try 16 - 9 = 7. Add 7 to the number set. Current number set: [7, 6, 18], target: 12. Options for choosing two numbers: [(7, 6), (7, 18), (6, 18)].
   |- Pick two numbers (7, 6) (numbers left: [18]). Try possible operations.
    |- Try 7 + 6 = 13. Add 13 to the number set. Current number set: [13, 18], target: 12, just two numbers left.
     |- Try 18 + 13 = 31. Evaluate 31 != 12, drop this branch.
     |- Try 18 - 13 = 5. Evaluate 5 != 12, drop this branch.
     |- Try 18 * 13 = 234. Evaluate 234 != 12, drop this branch.
     |- Try 18 / 13 = 1.4. 1.4 is a decimal, drop this branch.
    |- Try 7 - 6 = 1. Add 1 to the number set. Current number set: [1, 18], target: 12, just two numbers left.
     |- Try 18 + 1 = 19. Evaluate 19 != 12, drop this branch.
     |- Try 18 - 1 = 17. Evaluate 17 != 12, drop this branch.
     |- Try 18 * 1 = 18. Evaluate 18 != 12, drop this branch.
     |- Try 18 / 1 = 18. Evaluate 18 != 12, drop this branch.
    |- Try 7 * 6 = 42. Add 42 to the number set. Current number set: [42, 18], target: 12, just two numbers left.
     |- Try 42 + 18 = 60. Evaluate 60 != 12, drop this branch.
     |- Try 42 - 18 = 24. Evaluate 24 != 12, drop this branch.
     |- Try 42 * 18 = 756. Evaluate 756 != 12, drop this branch.
     |- Try 42 / 18 = 2.3. 2.3 is a decimal, drop this branch.
    |- Try 7 / 6 = 1.2. 1.2 is a decimal, drop this branch.
   |- Pick two numbers (7, 18) (numbers left: [6]). Try possible operations.
    |- Try 18 + 7 = 25. Add 25 to the number set. Current number set: [25, 6], target: 12, just two numbers left.
     |- Try 25 + 6 = 31. Evaluate 31 != 12, drop this branch.
     |- Try 25 - 6 = 19. Evaluate 19 != 12, drop this branch.
     |- Try 25 * 6 = 150. Evaluate 150 != 12, drop this branch.
     |- Try 25 / 6 = 4.2. 4.2 is a decimal, drop this branch.
    |- Try 18 - 7 = 11. Add 11 to the number set. Current number set: [11, 6], target: 12, just two numbers left.
     |- Try 11 + 6 = 17. Evaluate 17 != 12, drop this branch.
     |- Try 11 - 6 = 5. Evaluate 5 != 12, drop this branch.
     |- Try 11 * 6 = 66. Evaluate 66 != 12, drop this branch.
     |- Try 11 / 6 = 1.8. 1.8 is a decimal, drop this branch.
    |- Try 18 * 7 = 126. Add 126 to the number set. Current number set: [126, 6], target: 12, just two numbers left.
     |- Try 126 + 6 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 126 - 6 = 120. Evaluate 120 != 12, drop this branch.
     |- Try 126 * 6 = 756. Evaluate 756 != 12, drop this branch.
     |- Try 126 / 6 = 21. Evaluate 21 != 12, drop this branch.
    |- Try 18 / 7 = 2.6. 2.6 is a decimal, drop this branch.
   |- Pick two numbers (6, 18) (numbers left: [7]). Try possible operations.
    |- Try 18 + 6 = 24. Add 24 to the number set. Current number set: [24, 7], target: 12, just two numbers left.
     |- Try 24 + 7 = 31. Evaluate 31 != 12, drop this branch.
     |- Try 24 - 7 = 17. Evaluate 17 != 12, drop this branch.
     |- Try 24 * 7 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 24 / 7 = 3.4. 3.4 is a decimal, drop this branch.
    |- Try 18 - 6 = 12. Add 12 to the number set. Current number set: [12, 7], target: 12, just two numbers left.
     |- Try 12 + 7 = 19. Evaluate 19 != 12, drop this branch.
     |- Try 12 - 7 = 5. Evaluate 5 != 12, drop this branch.
     |- Try 12 * 7 = 84. Evaluate 84 != 12, drop this branch.
     |- Try 12 / 7 = 1.7. 1.7 is a decimal, drop this branch.
    |- Try 18 * 6 = 108. Add 108 to the number set. Current number set: [108, 7], target: 12, just two numbers left.
     |- Try 108 + 7 = 115. Evaluate 115 != 12, drop this branch.
     |- Try 108 - 7 = 101. Evaluate 101 != 12, drop this branch.
     |- Try 108 * 7 = 756. Evaluate 756 != 12, drop this branch.
     |- Try 108 / 7 = 15.4. 15.4 is a decimal, drop this branch.
    |- Try 18 / 6 = 3. Add 3 to the number set. Current number set: [3, 7], target: 12, just two numbers left.
     |- Try 7 + 3 = 10. Evaluate 10 != 12, drop this branch.
     |- Try 7 - 3 = 4. Evaluate 4 != 12, drop this branch.
     |- Try 7 * 3 = 21. Evaluate 21 != 12, drop this branch.
     |- Try 7 / 3 = 2.3. 2.3 is a decimal, drop this branch.
  |- Try 16 * 9 = 144. Add 144 to the number set. Current number set: [144, 6, 18], target: 12. Options for choosing two numbers: [(144, 6), (144, 18), (6, 18)].
   |- Pick two numbers (144, 6) (numbers left: [18]). Try possible operations.
    |- Try 144 + 6 = 150. Add 150 to the number set. Current number set: [150, 18], target: 12, just two numbers left.
     |- Try 150 + 18 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 150 - 18 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 150 * 18 = 2700. 2700 exceeds the maximum intermediate result, drop this branch.
     |- Try 150 / 18 = 8.3. 8.3 is a decimal, drop this branch.
    |- Try 144 - 6 = 138. Add 138 to the number set. Current number set: [138, 18], target: 12, just two numbers left.
     |- Try 138 + 18 = 156. Evaluate 156 != 12, drop this branch.
     |- Try 138 - 18 = 120. Evaluate 120 != 12, drop this branch.
     |- Try 138 * 18 = 2484. 2484 exceeds the maximum intermediate result, drop this branch.
     |- Try 138 / 18 = 7.7. 7.7 is a decimal, drop this branch.
    |- Try 144 * 6 = 864. Add 864 to the number set. Current number set: [864, 18], target: 12, just two numbers left.
     |- Try 864 + 18 = 882. Evaluate 882 != 12, drop this branch.
     |- Try 864 - 18 = 846. Evaluate 846 != 12, drop this branch.
     |- Try 864 * 18 = 15552. 15552 exceeds the maximum intermediate result, drop this branch.
     |- Try 864 / 18 = 48. Evaluate 48 != 12, drop this branch.
    |- Try 144 / 6 = 24. Add 24 to the number set. Current number set: [24, 18], target: 12, just two numbers left.
     |- Try 24 + 18 = 42. Evaluate 42 != 12, drop this branch.
     |- Try 24 - 18 = 6. Evaluate 6 != 12, drop this branch.
     |- Try 24 * 18 = 432. Evaluate 432 != 12, drop this branch.
     |- Try 24 / 18 = 1.3. 1.3 is a decimal, drop this branch.
   |- Pick two numbers (144, 18) (numbers left: [6]). Try possible operations.
    |- Try 144 + 18 = 162. Add 162 to the number set. Current number set: [162, 6], target: 12, just two numbers left.
     |- Try 162 + 6 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 162 - 6 = 156. Evaluate 156 != 12, drop this branch.
     |- Try 162 * 6 = 972. Evaluate 972 != 12, drop this branch.
     |- Try 162 / 6 = 27. Evaluate 27 != 12, drop this branch.
    |- Try 144 - 18 = 126. Add 126 to the number set. Current number set: [126, 6], target: 12, just two numbers left.
     |- Try 126 + 6 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 126 - 6 = 120. Evaluate 120 != 12, drop this branch.
     |- Try 126 * 6 = 756. Evaluate 756 != 12, drop this branch.
     |- Try 126 / 6 = 21. Evaluate 21 != 12, drop this branch.
    |- Try 144 * 18 = 2592. 2592 exceeds the maximum intermediate result, drop this branch.
    |- Try 144 / 18 = 8. Add 8 to the number set. Current number set: [8, 6], target: 12, just two numbers left.
     |- Try 8 + 6 = 14. Evaluate 14 != 12, drop this branch.
     |- Try 8 - 6 = 2. Evaluate 2 != 12, drop this branch.
     |- Try 8 * 6 = 48. Evaluate 48 != 12, drop this branch.
     |- Try 8 / 6 = 1.3. 1.3 is a decimal, drop this branch.
   |- Pick two numbers (6, 18) (numbers left: [144]). Try possible operations.
    |- Try 18 + 6 = 24. Add 24 to the number set. Current number set: [24, 144], target: 12, just two numbers left.
     |- Try 144 + 24 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 144 - 24 = 120. Evaluate 120 != 12, drop this branch.
     |- Try 144 * 24 = 3456. 3456 exceeds the maximum intermediate result, drop this branch.
     |- Try 144 / 24 = 6. Evaluate 6 != 12, drop this branch.
    |- Try 18 - 6 = 12. Add 12 to the number set. Current number set: [12, 144], target: 12, just two numbers left.
     |- Try 144 + 12 = 156. Evaluate 156 != 12, drop this branch.
     |- Try 144 - 12 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 144 * 12 = 1728. Evaluate 1728 != 12, drop this branch.
     |- Try 144 / 12 = 12. Evaluate 12 == 12, target found!

Now we have found the target, let's trace back the solution:
Final step: 144 / 12 = 12
The step before: 18 - 6 = 12
The first step: 16 * 9 = 144

Output the solution in the required format:
<Solution>
16 * 9 = 144
18 - 6 = 12
144 / 12 = 12
</Solution>

[Problem]
Now, solve the following problem. Note that:
- Please carefully read the approach and examples provided above, and follow them to solve the problem.
- Please ALWAYS include your search procedure (after # Search Procedure). The search procedure should follow the format of the examples provided above.
- Please mark your answer with <Solution> and </Solution> tags. The solution should be a sequence of three equations exactly following the format of the examples above, with no additional text in between.

Numbers: [30, 32, 42, 8]
Target: 36

# Search Procedure
Initial number set: [30, 32, 42, 8], target: 36. Options for choosing two numbers: [(30, 32), (30, 42), (30, 8), (32, 42), (32, 8), (42, 8)].
 |- Pick two numbers (30, 32) (numbers left: [42, 8]). Try possible operations.
  |- Try 32 + 30 = 62. Add 62 to the number set. Current number set: [62, 42, 8], target: 36. Options for choosing two numbers: [(62, 42), (62, 8), (42, 8)].
   |- Pick two numbers (62, 42) (numbers left: [8]). Try possible operations.
    |- Try 62 + 42 = 104. Add 104 to the number set. Current number set: [104, 8], target: 36, just two numbers left.
     |- Try 104 + 8 = 112. Evaluate 112 != 36, drop this branch.
     |- Try 104 - 8 = 96. Evaluate 96 != 36, drop this branch.
     |- Try 104 * 8 = 832. Evaluate 832 != 36, drop this branch.
     |- Try 104 / 8 = 13. Evaluate 13 != 36, drop this branch.
    |- Try 62 - 42 = 20. Add 20 to the number set. Current number set: [20, 8], target: 36, just two numbers left.
     |- Try 20 + 8 = 28. Evaluate 28 != 36, drop this branch.
     |- Try 20 - 8 = 12. Evaluate 12 != 36, drop this branch.
     |- Try 20 * 8 = 160. Evaluate 160 != 36, drop this branch.
     |- Try 20 / 8 = 2.5. 2.5 is a decimal, drop this branch.
    |- Try 62 * 42 = 2604. 2604 exceeds the maximum intermediate result, drop this branch.
    |- Try 62 / 42 = 1.5. 1.5 is a decimal, drop this branch.
   |- Pick two numbers (62, 8) (numbers left: [42]). Try possible operations.
    |- Try 62 + 8 = 70. Add 70 to the number set. Current number set: [70, 42], target: 36, just two numbers left.
     |- Try 70 + 42 = 112. Evaluate 112 != 36, drop this branch.
     |- Try 70 - 42 = 28. Evaluate 28 != 36, drop this branch.
     |- Try 70 * 42 = 2940. 2940 exceeds the maximum intermediate result, drop this branch.
     |- Try 70 / 42 = 1.7. 1.7 is a decimal, drop this branch.
    |- Try 62 - 8 = 54. Add 54 to the number set. Current number set: [54, 42], target: 36, just two numbers left.
     |- Try 54 + 42 = 96. Evaluate 96 != 36, drop this branch.
     |- Try 54 - 42 = 12. Evaluate 12 != 36, drop this branch.
     |- Try 54 * 42 = 2268. 2268 exceeds the maximum intermediate result, drop this branch.
     |- Try 54 / 42 = 1.3. 1.3 is a decimal, drop this branch.
    |- Try 62 * 8 = 496. Add 496 to the number set. Current number set: [496, 42], target: 36, just two numbers left.
     |- Try 496 + 42 = 538. Evaluate 538 != 36, drop this branch.
     |- Try 496 - 42 = 454. Evaluate 454 != 36, drop this branch.
     |- Try 496 * 42 = 20832. 20832 exceeds the maximum intermediate result, drop this branch.
     |- Try 496 / 42 = 11.8. 11.8 is a decimal, drop this branch.
    |- Try 62 / 8 = 7.8. 7.8 is a decimal, drop this branch.
   |- Pick two numbers (42, 8) (numbers left: [62]). Try possible operations.
    |- Try 42 + 8 = 50. Add 50 to the number set. Current number set: [50, 62], target: 36, just two numbers left.
     |- Try 62 + 50 = 112. Evaluate 112 != 36, drop this branch.
     |- Try 62 - 50 = 12. Evaluate 12 != 36, drop this branch.
     |- Try 62 * 50 = 3100. 3100 exceeds the maximum intermediate result, drop this branch.
     |- Try 62 / 50 = 1.2. 1.2 is a decimal, drop this branch.
    |- Try 42 - 8 = 34. Add 34 to the number set. Current number set: [34, 62], target: 36, just two numbers left.
     |- Try 62 + 34 = 96. Evaluate 96 != 36, drop this branch.
     |- Try 62 - 34 = 28. Evaluate 28 != 36, drop this branch.
     |- Try 62 * 34 = 2108. 2108 exceeds the maximum intermediate result, drop this branch.
     |- Try 62 / 34 = 1.8. 1.8 is a decimal, drop this branch.
    |- Try 42 * 8 = 336. Add 336 to the number set. Current number set: [336, 62], target: 36, just two numbers left.
     |- Try 336 + 62 = 398. Evaluate 398 != 36, drop this branch.
     |- Try 336 - 62 = 274. Evaluate 274 != 36, drop this branch.
     |- Try 336 * 62 = 20832. 20832 exceeds the maximum intermediate result, drop this branch.
     |- Try 336 / 62 = 5.4. 5.4 is a decimal, drop this branch.
    |- Try 42 / 8 = 5.2. 5.2 is a decimal, drop this branch.
  |- Try 32 - 30 = 2. Add 2 to the number set. Current number set: [2, 42, 8], target: 36. Options for choosing two numbers: [(2, 42), (2, 8), (42, 8)].
   |- Pick two numbers (2, 42) (numbers left: [8]). Try possible operations.
    |- Try 42 + 2 = 44. Add 44 to the number set. Current number set: [44, 8], target: 36, just two numbers left.
     |- Try 44 + 8 = 52. Evaluate 52 != 36, drop this branch.
     |- Try 44 - 8 = 36. Evaluate 36 == 36, target found!

Now we have found the target, let's trace back the solution:
Final step: 44 - 8 = 36
The step before: 42 + 2 = 44
The first step: 32 - 30 = 2

Output the solution in the required format:
<Solution>
32 - 30 = 2
42 + 2 = 44
44 - 8 = 36
</Solution>

Solution:
32 - 30 = 2
42 + 2 = 44
44 - 8 = 36


[TASK]
You will be given four numbers and a target number, your task is to find a way to use all four numbers exactly once, along with the basic operations (+, -, *, /), to reach the target number.

[RULES]
- You can use each number exactly once.
- You can use the four basic operations (+, -, *, /).
- The intermediate results must be integers (no decimals allowed).
- The intermediate results must be positive.
- The intermediate results will not exceed 2000.

[APPROACH]
We will solve the problem by searching. Starting from a given set of four numbers, we will follow this search process:
- At each state, we will consider all possible number pairs (in order) from the current number set. Choose one pair and apply one of the four basic operations to them to obtain a new number.
  * If there are still numbers left, we will add the new number to the number set and continue the search.
  * If we have used all numbers, we will check if the new number is equal to the target number. If it is, we have found the solution. Otherwise, we will backtrack.
- Suppose the two numbers we choose are a and b (where a >= b). We will try the four options (a + b), (a - b), (a * b), (a / b) to obtain the new number. Remember to always use the larger number as the first operand.
- If the new number is a decimal, or exceeds the maximum intermediate result, we will discard this branch and backtrack.
- We will continue this process until we reach the target number with four numbers used or exhaust all possible combinations.

[EXAMPLES]
# Example
Numbers: [40, 19, 23, 7]
Target: 29

# Search Procedure
Initial number set: [40, 19, 23, 7], target: 29. Options for choosing two numbers: [(40, 19), (40, 23), (40, 7), (19, 23), (19, 7), (23, 7)].
 |- Pick two numbers (40, 19) (numbers left: [23, 7]). Try possible operations.
  |- Try 40 + 19 = 59. Add 59 to the number set. Current number set: [59, 23, 7], target: 29. Options for choosing two numbers: [(59, 23), (59, 7), (23, 7)].
   |- Pick two numbers (59, 23) (numbers left: [7]). Try possible operations.
    |- Try 59 + 23 = 82. Add 82 to the number set. Current number set: [82, 7], target: 29, just two numbers left.
     |- Try 82 + 7 = 89. Evaluate 89 != 29, drop this branch.
     |- Try 82 - 7 = 75. Evaluate 75 != 29, drop this branch.
     |- Try 82 * 7 = 574. Evaluate 574 != 29, drop this branch.
     |- Try 82 / 7 = 11.7. 11.7 is a decimal, drop this branch.
    |- Try 59 - 23 = 36. Add 36 to the number set. Current number set: [36, 7], target: 29, just two numbers left.
     |- Try 36 + 7 = 43. Evaluate 43 != 29, drop this branch.
     |- Try 36 - 7 = 29. Evaluate 29 == 29, target found!

Now we have found the target, let's trace back the solution:
Final step: 36 - 7 = 29
The step before: 59 - 23 = 36
The first step: 40 + 19 = 59

Output the solution in the required format:
<Solution>
40 + 19 = 59
59 - 23 = 36
36 - 7 = 29
</Solution>

# Example
Numbers: [9, 16, 6, 18]
Target: 12

# Search Procedure
Initial number set: [9, 16, 6, 18], target: 12. Options for choosing two numbers: [(9, 16), (9, 6), (9, 18), (16, 6), (16, 18), (6, 18)].
 |- Pick two numbers (9, 16) (numbers left: [6, 18]). Try possible operations.
  |- Try 16 + 9 = 25. Add 25 to the number set. Current number set: [25, 6, 18], target: 12. Options for choosing two numbers: [(25, 6), (25, 18), (6, 18)].
   |- Pick two numbers (25, 6) (numbers left: [18]). Try possible operations.
    |- Try 25 + 6 = 31. Add 31 to the number set. Current number set: [31, 18], target: 12, just two numbers left.
     |- Try 31 + 18 = 49. Evaluate 49 != 12, drop this branch.
     |- Try 31 - 18 = 13. Evaluate 13 != 12, drop this branch.
     |- Try 31 * 18 = 558. Evaluate 558 != 12, drop this branch.
     |- Try 31 / 18 = 1.7. 1.7 is a decimal, drop this branch.
    |- Try 25 - 6 = 19. Add 19 to the number set. Current number set: [19, 18], target: 12, just two numbers left.
     |- Try 19 + 18 = 37. Evaluate 37 != 12, drop this branch.
     |- Try 19 - 18 = 1. Evaluate 1 != 12, drop this branch.
     |- Try 19 * 18 = 342. Evaluate 342 != 12, drop this branch.
     |- Try 19 / 18 = 1.1. 1.1 is a decimal, drop this branch.
    |- Try 25 * 6 = 150. Add 150 to the number set. Current number set: [150, 18], target: 12, just two numbers left.
     |- Try 150 + 18 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 150 - 18 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 150 * 18 = 2700. 2700 exceeds the maximum intermediate result, drop this branch.
     |- Try 150 / 18 = 8.3. 8.3 is a decimal, drop this branch.
    |- Try 25 / 6 = 4.2. 4.2 is a decimal, drop this branch.
   |- Pick two numbers (25, 18) (numbers left: [6]). Try possible operations.
    |- Try 25 + 18 = 43. Add 43 to the number set. Current number set: [43, 6], target: 12, just two numbers left.
     |- Try 43 + 6 = 49. Evaluate 49 != 12, drop this branch.
     |- Try 43 - 6 = 37. Evaluate 37 != 12, drop this branch.
     |- Try 43 * 6 = 258. Evaluate 258 != 12, drop this branch.
     |- Try 43 / 6 = 7.2. 7.2 is a decimal, drop this branch.
    |- Try 25 - 18 = 7. Add 7 to the number set. Current number set: [7, 6], target: 12, just two numbers left.
     |- Try 7 + 6 = 13. Evaluate 13 != 12, drop this branch.
     |- Try 7 - 6 = 1. Evaluate 1 != 12, drop this branch.
     |- Try 7 * 6 = 42. Evaluate 42 != 12, drop this branch.
     |- Try 7 / 6 = 1.2. 1.2 is a decimal, drop this branch.
    |- Try 25 * 18 = 450. Add 450 to the number set. Current number set: [450, 6], target: 12, just two numbers left.
     |- Try 450 + 6 = 456. Evaluate 456 != 12, drop this branch.
     |- Try 450 - 6 = 444. Evaluate 444 != 12, drop this branch.
     |- Try 450 * 6 = 2700. 2700 exceeds the maximum intermediate result, drop this branch.
     |- Try 450 / 6 = 75. Evaluate 75 != 12, drop this branch.
    |- Try 25 / 18 = 1.4. 1.4 is a decimal, drop this branch.
   |- Pick two numbers (6, 18) (numbers left: [25]). Try possible operations.
    |- Try 18 + 6 = 24. Add 24 to the number set. Current number set: [24, 25], target: 12, just two numbers left.
     |- Try 25 + 24 = 49. Evaluate 49 != 12, drop this branch.
     |- Try 25 - 24 = 1. Evaluate 1 != 12, drop this branch.
     |- Try 25 * 24 = 600. Evaluate 600 != 12, drop this branch.
     |- Try 25 / 24 = 1.0. 1.0 is a decimal, drop this branch.
    |- Try 18 - 6 = 12. Add 12 to the number set. Current number set: [12, 25], target: 12, just two numbers left.
     |- Try 25 + 12 = 37. Evaluate 37 != 12, drop this branch.
     |- Try 25 - 12 = 13. Evaluate 13 != 12, drop this branch.
     |- Try 25 * 12 = 300. Evaluate 300 != 12, drop this branch.
     |- Try 25 / 12 = 2.1. 2.1 is a decimal, drop this branch.
    |- Try 18 * 6 = 108. Add 108 to the number set. Current number set: [108, 25], target: 12, just two numbers left.
     |- Try 108 + 25 = 133. Evaluate 133 != 12, drop this branch.
     |- Try 108 - 25 = 83. Evaluate 83 != 12, drop this branch.
     |- Try 108 * 25 = 2700. 2700 exceeds the maximum intermediate result, drop this branch.
     |- Try 108 / 25 = 4.3. 4.3 is a decimal, drop this branch.
    |- Try 18 / 6 = 3. Add 3 to the number set. Current number set: [3, 25], target: 12, just two numbers left.
     |- Try 25 + 3 = 28. Evaluate 28 != 12, drop this branch.
     |- Try 25 - 3 = 22. Evaluate 22 != 12, drop this branch.
     |- Try 25 * 3 = 75. Evaluate 75 != 12, drop this branch.
     |- Try 25 / 3 = 8.3. 8.3 is a decimal, drop this branch.
  |- Try 16 - 9 = 7. Add 7 to the number set. Current number set: [7, 6, 18], target: 12. Options for choosing two numbers: [(7, 6), (7, 18), (6, 18)].
   |- Pick two numbers (7, 6) (numbers left: [18]). Try possible operations.
    |- Try 7 + 6 = 13. Add 13 to the number set. Current number set: [13, 18], target: 12, just two numbers left.
     |- Try 18 + 13 = 31. Evaluate 31 != 12, drop this branch.
     |- Try 18 - 13 = 5. Evaluate 5 != 12, drop this branch.
     |- Try 18 * 13 = 234. Evaluate 234 != 12, drop this branch.
     |- Try 18 / 13 = 1.4. 1.4 is a decimal, drop this branch.
    |- Try 7 - 6 = 1. Add 1 to the number set. Current number set: [1, 18], target: 12, just two numbers left.
     |- Try 18 + 1 = 19. Evaluate 19 != 12, drop this branch.
     |- Try 18 - 1 = 17. Evaluate 17 != 12, drop this branch.
     |- Try 18 * 1 = 18. Evaluate 18 != 12, drop this branch.
     |- Try 18 / 1 = 18. Evaluate 18 != 12, drop this branch.
    |- Try 7 * 6 = 42. Add 42 to the number set. Current number set: [42, 18], target: 12, just two numbers left.
     |- Try 42 + 18 = 60. Evaluate 60 != 12, drop this branch.
     |- Try 42 - 18 = 24. Evaluate 24 != 12, drop this branch.
     |- Try 42 * 18 = 756. Evaluate 756 != 12, drop this branch.
     |- Try 42 / 18 = 2.3. 2.3 is a decimal, drop this branch.
    |- Try 7 / 6 = 1.2. 1.2 is a decimal, drop this branch.
   |- Pick two numbers (7, 18) (numbers left: [6]). Try possible operations.
    |- Try 18 + 7 = 25. Add 25 to the number set. Current number set: [25, 6], target: 12, just two numbers left.
     |- Try 25 + 6 = 31. Evaluate 31 != 12, drop this branch.
     |- Try 25 - 6 = 19. Evaluate 19 != 12, drop this branch.
     |- Try 25 * 6 = 150. Evaluate 150 != 12, drop this branch.
     |- Try 25 / 6 = 4.2. 4.2 is a decimal, drop this branch.
    |- Try 18 - 7 = 11. Add 11 to the number set. Current number set: [11, 6], target: 12, just two numbers left.
     |- Try 11 + 6 = 17. Evaluate 17 != 12, drop this branch.
     |- Try 11 - 6 = 5. Evaluate 5 != 12, drop this branch.
     |- Try 11 * 6 = 66. Evaluate 66 != 12, drop this branch.
     |- Try 11 / 6 = 1.8. 1.8 is a decimal, drop this branch.
    |- Try 18 * 7 = 126. Add 126 to the number set. Current number set: [126, 6], target: 12, just two numbers left.
     |- Try 126 + 6 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 126 - 6 = 120. Evaluate 120 != 12, drop this branch.
     |- Try 126 * 6 = 756. Evaluate 756 != 12, drop this branch.
     |- Try 126 / 6 = 21. Evaluate 21 != 12, drop this branch.
    |- Try 18 / 7 = 2.6. 2.6 is a decimal, drop this branch.
   |- Pick two numbers (6, 18) (numbers left: [7]). Try possible operations.
    |- Try 18 + 6 = 24. Add 24 to the number set. Current number set: [24, 7], target: 12, just two numbers left.
     |- Try 24 + 7 = 31. Evaluate 31 != 12, drop this branch.
     |- Try 24 - 7 = 17. Evaluate 17 != 12, drop this branch.
     |- Try 24 * 7 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 24 / 7 = 3.4. 3.4 is a decimal, drop this branch.
    |- Try 18 - 6 = 12. Add 12 to the number set. Current number set: [12, 7], target: 12, just two numbers left.
     |- Try 12 + 7 = 19. Evaluate 19 != 12, drop this branch.
     |- Try 12 - 7 = 5. Evaluate 5 != 12, drop this branch.
     |- Try 12 * 7 = 84. Evaluate 84 != 12, drop this branch.
     |- Try 12 / 7 = 1.7. 1.7 is a decimal, drop this branch.
    |- Try 18 * 6 = 108. Add 108 to the number set. Current number set: [108, 7], target: 12, just two numbers left.
     |- Try 108 + 7 = 115. Evaluate 115 != 12, drop this branch.
     |- Try 108 - 7 = 101. Evaluate 101 != 12, drop this branch.
     |- Try 108 * 7 = 756. Evaluate 756 != 12, drop this branch.
     |- Try 108 / 7 = 15.4. 15.4 is a decimal, drop this branch.
    |- Try 18 / 6 = 3. Add 3 to the number set. Current number set: [3, 7], target: 12, just two numbers left.
     |- Try 7 + 3 = 10. Evaluate 10 != 12, drop this branch.
     |- Try 7 - 3 = 4. Evaluate 4 != 12, drop this branch.
     |- Try 7 * 3 = 21. Evaluate 21 != 12, drop this branch.
     |- Try 7 / 3 = 2.3. 2.3 is a decimal, drop this branch.
  |- Try 16 * 9 = 144. Add 144 to the number set. Current number set: [144, 6, 18], target: 12. Options for choosing two numbers: [(144, 6), (144, 18), (6, 18)].
   |- Pick two numbers (144, 6) (numbers left: [18]). Try possible operations.
    |- Try 144 + 6 = 150. Add 150 to the number set. Current number set: [150, 18], target: 12, just two numbers left.
     |- Try 150 + 18 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 150 - 18 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 150 * 18 = 2700. 2700 exceeds the maximum intermediate result, drop this branch.
     |- Try 150 / 18 = 8.3. 8.3 is a decimal, drop this branch.
    |- Try 144 - 6 = 138. Add 138 to the number set. Current number set: [138, 18], target: 12, just two numbers left.
     |- Try 138 + 18 = 156. Evaluate 156 != 12, drop this branch.
     |- Try 138 - 18 = 120. Evaluate 120 != 12, drop this branch.
     |- Try 138 * 18 = 2484. 2484 exceeds the maximum intermediate result, drop this branch.
     |- Try 138 / 18 = 7.7. 7.7 is a decimal, drop this branch.
    |- Try 144 * 6 = 864. Add 864 to the number set. Current number set: [864, 18], target: 12, just two numbers left.
     |- Try 864 + 18 = 882. Evaluate 882 != 12, drop this branch.
     |- Try 864 - 18 = 846. Evaluate 846 != 12, drop this branch.
     |- Try 864 * 18 = 15552. 15552 exceeds the maximum intermediate result, drop this branch.
     |- Try 864 / 18 = 48. Evaluate 48 != 12, drop this branch.
    |- Try 144 / 6 = 24. Add 24 to the number set. Current number set: [24, 18], target: 12, just two numbers left.
     |- Try 24 + 18 = 42. Evaluate 42 != 12, drop this branch.
     |- Try 24 - 18 = 6. Evaluate 6 != 12, drop this branch.
     |- Try 24 * 18 = 432. Evaluate 432 != 12, drop this branch.
     |- Try 24 / 18 = 1.3. 1.3 is a decimal, drop this branch.
   |- Pick two numbers (144, 18) (numbers left: [6]). Try possible operations.
    |- Try 144 + 18 = 162. Add 162 to the number set. Current number set: [162, 6], target: 12, just two numbers left.
     |- Try 162 + 6 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 162 - 6 = 156. Evaluate 156 != 12, drop this branch.
     |- Try 162 * 6 = 972. Evaluate 972 != 12, drop this branch.
     |- Try 162 / 6 = 27. Evaluate 27 != 12, drop this branch.
    |- Try 144 - 18 = 126. Add 126 to the number set. Current number set: [126, 6], target: 12, just two numbers left.
     |- Try 126 + 6 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 126 - 6 = 120. Evaluate 120 != 12, drop this branch.
     |- Try 126 * 6 = 756. Evaluate 756 != 12, drop this branch.
     |- Try 126 / 6 = 21. Evaluate 21 != 12, drop this branch.
    |- Try 144 * 18 = 2592. 2592 exceeds the maximum intermediate result, drop this branch.
    |- Try 144 / 18 = 8. Add 8 to the number set. Current number set: [8, 6], target: 12, just two numbers left.
     |- Try 8 + 6 = 14. Evaluate 14 != 12, drop this branch.
     |- Try 8 - 6 = 2. Evaluate 2 != 12, drop this branch.
     |- Try 8 * 6 = 48. Evaluate 48 != 12, drop this branch.
     |- Try 8 / 6 = 1.3. 1.3 is a decimal, drop this branch.
   |- Pick two numbers (6, 18) (numbers left: [144]). Try possible operations.
    |- Try 18 + 6 = 24. Add 24 to the number set. Current number set: [24, 144], target: 12, just two numbers left.
     |- Try 144 + 24 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 144 - 24 = 120. Evaluate 120 != 12, drop this branch.
     |- Try 144 * 24 = 3456. 3456 exceeds the maximum intermediate result, drop this branch.
     |- Try 144 / 24 = 6. Evaluate 6 != 12, drop this branch.
    |- Try 18 - 6 = 12. Add 12 to the number set. Current number set: [12, 144], target: 12, just two numbers left.
     |- Try 144 + 12 = 156. Evaluate 156 != 12, drop this branch.
     |- Try 144 - 12 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 144 * 12 = 1728. Evaluate 1728 != 12, drop this branch.
     |- Try 144 / 12 = 12. Evaluate 12 == 12, target found!

Now we have found the target, let's trace back the solution:
Final step: 144 / 12 = 12
The step before: 18 - 6 = 12
The first step: 16 * 9 = 144

Output the solution in the required format:
<Solution>
16 * 9 = 144
18 - 6 = 12
144 / 12 = 12
</Solution>

[Problem]
Now, solve the following problem. Note that:
- Please carefully read the approach and examples provided above, and follow them to solve the problem.
- Please ALWAYS include your search procedure (after # Search Procedure). The search procedure should follow the format of the examples provided above.
- Please mark your answer with <Solution> and </Solution> tags. The solution should be a sequence of three equations exactly following the format of the examples above, with no additional text in between.

Numbers: [10, 26, 33, 28]
Target: 45

# Search Procedure
Initial number set: [10, 26, 33, 28], target: 45. Options for choosing two numbers: [(10, 26), (10, 33), (10, 28), (26, 33), (26, 28), (33, 28)].
 |- Pick two numbers (10, 26) (numbers left: [33, 28]). Try possible operations.
  |- Try 26 + 10 = 36. Add 36 to the number set. Current number set: [36, 33, 28], target: 45. Options for choosing two numbers: [(36, 33), (36, 28), (33, 28)].
   |- Pick two numbers (36, 33) (numbers left: [28]). Try possible operations.
    |- Try 36 + 33 = 69. Add 69 to the number set. Current number set: [69, 28], target: 45, just two numbers left.
     |- Try 69 + 28 = 97. Evaluate 97 != 45, drop this branch.
     |- Try 69 - 28 = 41. Evaluate 41 != 45, drop this branch.
     |- Try 69 * 28 = 1932. Evaluate 1932 != 45, drop this branch.
     |- Try 69 / 28 = 2.5. 2.5 is a decimal, drop this branch.
    |- Try 36 - 33 = 3. Add 3 to the number set. Current number set: [3, 28], target: 45, just two numbers left.
     |- Try 28 + 3 = 31. Evaluate 31 != 45, drop this branch.
     |- Try 28 - 3 = 25. Evaluate 25 != 45, drop this branch.
     |- Try 28 * 3 = 84. Evaluate 84 != 45, drop this branch.
     |- Try 28 / 3 = 9.3. 9.3 is a decimal, drop this branch.
    |- Try 36 * 33 = 1188. Add 1188 to the number set. Current number set: [1188, 28], target: 45, just two numbers left.
     |- Try 1188 + 28 = 1216. Evaluate 1216 != 45, drop this branch.
     |- Try 1188 - 28 = 1160. Evaluate 1160 != 45, drop this branch.
     |- Try 1188 * 28 = 33264. 33264 exceeds the maximum intermediate result, drop this branch.
     |- Try 1188 / 28 = 42.4. 42.4 is a decimal, drop this branch.
    |- Try 36 / 33 = 1.1. 1.1 is a decimal, drop this branch.
   |- Pick two numbers (36, 28) (numbers left: [33]). Try possible operations.
    |- Try 36 + 28 = 64. Add 64 to the number set. Current number set: [64, 33], target: 45, just two numbers left.
     |- Try 64 + 33 = 97. Evaluate 97 != 45, drop this branch.
     |- Try 64 - 33 = 31. Evaluate 31 != 45, drop this branch.
     |- Try 64 * 33 = 2112. 2112 exceeds the maximum intermediate result, drop this branch.
     |- Try 64 / 33 = 1.9. 1.9 is a decimal, drop this branch.
    |- Try 36 - 28 = 8. Add 8 to the number set. Current number set: [8, 33], target: 45, just two numbers left.
     |- Try 33 + 8 = 41. Evaluate 41 != 45, drop this branch.
     |- Try 33 - 8 = 25. Evaluate 25 != 45, drop this branch.
     |- Try 33 * 8 = 264. Evaluate 264 != 45, drop this branch.
     |- Try 33 / 8 = 4.1. 4.1 is a decimal, drop this branch.
    |- Try 36 * 28 = 1008. Add 1008 to the number set. Current number set: [1008, 33], target: 45, just two numbers left.
     |- Try 1008 + 33 = 1041. Evaluate 1041 != 45, drop this branch.
     |- Try 1008 - 33 = 975. Evaluate 975 != 45, drop this branch.
     |- Try 1008 * 33 = 33264. 33264 exceeds the maximum intermediate result, drop this branch.
     |- Try 1008 / 33 = 30.5. 30.5 is a decimal, drop this branch.
    |- Try 36 / 28 = 1.3. 1.3 is a decimal, drop this branch.
   |- Pick two numbers (33, 28) (numbers left: [36]). Try possible operations.
    |- Try 33 + 28 = 61. Add 61 to the number set. Current number set: [61, 36], target: 45, just two numbers left.
     |- Try 61 + 36 = 97. Evaluate 97 != 45, drop this branch.
     |- Try 61 - 36 = 25. Evaluate 25 != 45, drop this branch.
     |- Try 61 * 36 = 2196. 2196 exceeds the maximum intermediate result, drop this branch.
     |- Try 61 / 36 = 1.7. 1.7 is a decimal, drop this branch.
    |- Try 33 - 28 = 5. Add 5 to the number set. Current number set: [5, 36], target: 45, just two numbers left.
     |- Try 36 + 5 = 41. Evaluate 41 != 45, drop this branch.
     |- Try 36 - 5 = 31. Evaluate 31 != 45, drop this branch.
     |- Try 36 * 5 = 180. Evaluate 180 != 45, drop this branch.
     |- Try 36 / 5 = 7.2. 7.2 is a decimal, drop this branch.
    |- Try 33 * 28 = 924. Add 924 to the number set. Current number set: [924, 36], target: 45, just two numbers left.
     |- Try 924 + 36 = 960. Evaluate 960 != 45, drop this branch.
     |- Try 924 - 36 = 888. Evaluate 888 != 45, drop this branch.
     |- Try 924 * 36 = 33264. 33264 exceeds the maximum intermediate result, drop this branch.
     |- Try 924 / 36 = 25.7. 25.7 is a decimal, drop this branch.
    |- Try 33 / 28 = 1.2. 1.2 is a decimal, drop this branch.
  |- Try 26 - 10 = 16. Add 16 to the number set. Current number set: [16, 33, 28], target: 45. Options for choosing two numbers: [(16, 33), (16, 28), (33, 28)].
   |- Pick two numbers (16, 33) (numbers left: [28]). Try possible operations.
    |- Try 33 + 16 = 49. Add 49 to the number set. Current number set: [49, 28], target: 45, just two numbers left.
     |- Try 49 + 28 = 77. Evaluate 77 != 45, drop this branch.
     |- Try 49 - 28 = 21. Evaluate 21 != 45, drop this branch.
     |- Try 49 * 28 = 1372. Evaluate 1372 != 45, drop this branch.
     |- Try 49 / 28 = 1.8. 1.8 is a decimal, drop this branch.
    |- Try 33 - 16 = 17. Add 17 to the number set. Current number set: [17, 28], target: 45, just two numbers left.
     |- Try 28 + 17 = 45. Evaluate 45 == 45, target found!

Now we have found the target, let's trace back the solution:
Final step: 28 + 17 = 45
The step before: 33 - 16 = 17
The first step: 26 - 10 = 16

Output the solution in the required format:
<Solution>
26 - 10 = 16
33 - 16 = 17
28 + 17 = 45
</Solution>

Solution:
26 - 10 = 16
33 - 16 = 17
28 + 17 = 45


[TASK]
You will be given four numbers and a target number, your task is to find a way to use all four numbers exactly once, along with the basic operations (+, -, *, /), to reach the target number.

[RULES]
- You can use each number exactly once.
- You can use the four basic operations (+, -, *, /).
- The intermediate results must be integers (no decimals allowed).
- The intermediate results must be positive.
- The intermediate results will not exceed 2000.

[APPROACH]
We will solve the problem by searching. Starting from a given set of four numbers, we will follow this search process:
- At each state, we will consider all possible number pairs (in order) from the current number set. Choose one pair and apply one of the four basic operations to them to obtain a new number.
  * If there are still numbers left, we will add the new number to the number set and continue the search.
  * If we have used all numbers, we will check if the new number is equal to the target number. If it is, we have found the solution. Otherwise, we will backtrack.
- Suppose the two numbers we choose are a and b (where a >= b). We will try the four options (a + b), (a - b), (a * b), (a / b) to obtain the new number. Remember to always use the larger number as the first operand.
- If the new number is a decimal, or exceeds the maximum intermediate result, we will discard this branch and backtrack.
- We will continue this process until we reach the target number with four numbers used or exhaust all possible combinations.

[EXAMPLES]
# Example
Numbers: [40, 19, 23, 7]
Target: 29

# Search Procedure
Initial number set: [40, 19, 23, 7], target: 29. Options for choosing two numbers: [(40, 19), (40, 23), (40, 7), (19, 23), (19, 7), (23, 7)].
 |- Pick two numbers (40, 19) (numbers left: [23, 7]). Try possible operations.
  |- Try 40 + 19 = 59. Add 59 to the number set. Current number set: [59, 23, 7], target: 29. Options for choosing two numbers: [(59, 23), (59, 7), (23, 7)].
   |- Pick two numbers (59, 23) (numbers left: [7]). Try possible operations.
    |- Try 59 + 23 = 82. Add 82 to the number set. Current number set: [82, 7], target: 29, just two numbers left.
     |- Try 82 + 7 = 89. Evaluate 89 != 29, drop this branch.
     |- Try 82 - 7 = 75. Evaluate 75 != 29, drop this branch.
     |- Try 82 * 7 = 574. Evaluate 574 != 29, drop this branch.
     |- Try 82 / 7 = 11.7. 11.7 is a decimal, drop this branch.
    |- Try 59 - 23 = 36. Add 36 to the number set. Current number set: [36, 7], target: 29, just two numbers left.
     |- Try 36 + 7 = 43. Evaluate 43 != 29, drop this branch.
     |- Try 36 - 7 = 29. Evaluate 29 == 29, target found!

Now we have found the target, let's trace back the solution:
Final step: 36 - 7 = 29
The step before: 59 - 23 = 36
The first step: 40 + 19 = 59

Output the solution in the required format:
<Solution>
40 + 19 = 59
59 - 23 = 36
36 - 7 = 29
</Solution>

# Example
Numbers: [9, 16, 6, 18]
Target: 12

# Search Procedure
Initial number set: [9, 16, 6, 18], target: 12. Options for choosing two numbers: [(9, 16), (9, 6), (9, 18), (16, 6), (16, 18), (6, 18)].
 |- Pick two numbers (9, 16) (numbers left: [6, 18]). Try possible operations.
  |- Try 16 + 9 = 25. Add 25 to the number set. Current number set: [25, 6, 18], target: 12. Options for choosing two numbers: [(25, 6), (25, 18), (6, 18)].
   |- Pick two numbers (25, 6) (numbers left: [18]). Try possible operations.
    |- Try 25 + 6 = 31. Add 31 to the number set. Current number set: [31, 18], target: 12, just two numbers left.
     |- Try 31 + 18 = 49. Evaluate 49 != 12, drop this branch.
     |- Try 31 - 18 = 13. Evaluate 13 != 12, drop this branch.
     |- Try 31 * 18 = 558. Evaluate 558 != 12, drop this branch.
     |- Try 31 / 18 = 1.7. 1.7 is a decimal, drop this branch.
    |- Try 25 - 6 = 19. Add 19 to the number set. Current number set: [19, 18], target: 12, just two numbers left.
     |- Try 19 + 18 = 37. Evaluate 37 != 12, drop this branch.
     |- Try 19 - 18 = 1. Evaluate 1 != 12, drop this branch.
     |- Try 19 * 18 = 342. Evaluate 342 != 12, drop this branch.
     |- Try 19 / 18 = 1.1. 1.1 is a decimal, drop this branch.
    |- Try 25 * 6 = 150. Add 150 to the number set. Current number set: [150, 18], target: 12, just two numbers left.
     |- Try 150 + 18 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 150 - 18 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 150 * 18 = 2700. 2700 exceeds the maximum intermediate result, drop this branch.
     |- Try 150 / 18 = 8.3. 8.3 is a decimal, drop this branch.
    |- Try 25 / 6 = 4.2. 4.2 is a decimal, drop this branch.
   |- Pick two numbers (25, 18) (numbers left: [6]). Try possible operations.
    |- Try 25 + 18 = 43. Add 43 to the number set. Current number set: [43, 6], target: 12, just two numbers left.
     |- Try 43 + 6 = 49. Evaluate 49 != 12, drop this branch.
     |- Try 43 - 6 = 37. Evaluate 37 != 12, drop this branch.
     |- Try 43 * 6 = 258. Evaluate 258 != 12, drop this branch.
     |- Try 43 / 6 = 7.2. 7.2 is a decimal, drop this branch.
    |- Try 25 - 18 = 7. Add 7 to the number set. Current number set: [7, 6], target: 12, just two numbers left.
     |- Try 7 + 6 = 13. Evaluate 13 != 12, drop this branch.
     |- Try 7 - 6 = 1. Evaluate 1 != 12, drop this branch.
     |- Try 7 * 6 = 42. Evaluate 42 != 12, drop this branch.
     |- Try 7 / 6 = 1.2. 1.2 is a decimal, drop this branch.
    |- Try 25 * 18 = 450. Add 450 to the number set. Current number set: [450, 6], target: 12, just two numbers left.
     |- Try 450 + 6 = 456. Evaluate 456 != 12, drop this branch.
     |- Try 450 - 6 = 444. Evaluate 444 != 12, drop this branch.
     |- Try 450 * 6 = 2700. 2700 exceeds the maximum intermediate result, drop this branch.
     |- Try 450 / 6 = 75. Evaluate 75 != 12, drop this branch.
    |- Try 25 / 18 = 1.4. 1.4 is a decimal, drop this branch.
   |- Pick two numbers (6, 18) (numbers left: [25]). Try possible operations.
    |- Try 18 + 6 = 24. Add 24 to the number set. Current number set: [24, 25], target: 12, just two numbers left.
     |- Try 25 + 24 = 49. Evaluate 49 != 12, drop this branch.
     |- Try 25 - 24 = 1. Evaluate 1 != 12, drop this branch.
     |- Try 25 * 24 = 600. Evaluate 600 != 12, drop this branch.
     |- Try 25 / 24 = 1.0. 1.0 is a decimal, drop this branch.
    |- Try 18 - 6 = 12. Add 12 to the number set. Current number set: [12, 25], target: 12, just two numbers left.
     |- Try 25 + 12 = 37. Evaluate 37 != 12, drop this branch.
     |- Try 25 - 12 = 13. Evaluate 13 != 12, drop this branch.
     |- Try 25 * 12 = 300. Evaluate 300 != 12, drop this branch.
     |- Try 25 / 12 = 2.1. 2.1 is a decimal, drop this branch.
    |- Try 18 * 6 = 108. Add 108 to the number set. Current number set: [108, 25], target: 12, just two numbers left.
     |- Try 108 + 25 = 133. Evaluate 133 != 12, drop this branch.
     |- Try 108 - 25 = 83. Evaluate 83 != 12, drop this branch.
     |- Try 108 * 25 = 2700. 2700 exceeds the maximum intermediate result, drop this branch.
     |- Try 108 / 25 = 4.3. 4.3 is a decimal, drop this branch.
    |- Try 18 / 6 = 3. Add 3 to the number set. Current number set: [3, 25], target: 12, just two numbers left.
     |- Try 25 + 3 = 28. Evaluate 28 != 12, drop this branch.
     |- Try 25 - 3 = 22. Evaluate 22 != 12, drop this branch.
     |- Try 25 * 3 = 75. Evaluate 75 != 12, drop this branch.
     |- Try 25 / 3 = 8.3. 8.3 is a decimal, drop this branch.
  |- Try 16 - 9 = 7. Add 7 to the number set. Current number set: [7, 6, 18], target: 12. Options for choosing two numbers: [(7, 6), (7, 18), (6, 18)].
   |- Pick two numbers (7, 6) (numbers left: [18]). Try possible operations.
    |- Try 7 + 6 = 13. Add 13 to the number set. Current number set: [13, 18], target: 12, just two numbers left.
     |- Try 18 + 13 = 31. Evaluate 31 != 12, drop this branch.
     |- Try 18 - 13 = 5. Evaluate 5 != 12, drop this branch.
     |- Try 18 * 13 = 234. Evaluate 234 != 12, drop this branch.
     |- Try 18 / 13 = 1.4. 1.4 is a decimal, drop this branch.
    |- Try 7 - 6 = 1. Add 1 to the number set. Current number set: [1, 18], target: 12, just two numbers left.
     |- Try 18 + 1 = 19. Evaluate 19 != 12, drop this branch.
     |- Try 18 - 1 = 17. Evaluate 17 != 12, drop this branch.
     |- Try 18 * 1 = 18. Evaluate 18 != 12, drop this branch.
     |- Try 18 / 1 = 18. Evaluate 18 != 12, drop this branch.
    |- Try 7 * 6 = 42. Add 42 to the number set. Current number set: [42, 18], target: 12, just two numbers left.
     |- Try 42 + 18 = 60. Evaluate 60 != 12, drop this branch.
     |- Try 42 - 18 = 24. Evaluate 24 != 12, drop this branch.
     |- Try 42 * 18 = 756. Evaluate 756 != 12, drop this branch.
     |- Try 42 / 18 = 2.3. 2.3 is a decimal, drop this branch.
    |- Try 7 / 6 = 1.2. 1.2 is a decimal, drop this branch.
   |- Pick two numbers (7, 18) (numbers left: [6]). Try possible operations.
    |- Try 18 + 7 = 25. Add 25 to the number set. Current number set: [25, 6], target: 12, just two numbers left.
     |- Try 25 + 6 = 31. Evaluate 31 != 12, drop this branch.
     |- Try 25 - 6 = 19. Evaluate 19 != 12, drop this branch.
     |- Try 25 * 6 = 150. Evaluate 150 != 12, drop this branch.
     |- Try 25 / 6 = 4.2. 4.2 is a decimal, drop this branch.
    |- Try 18 - 7 = 11. Add 11 to the number set. Current number set: [11, 6], target: 12, just two numbers left.
     |- Try 11 + 6 = 17. Evaluate 17 != 12, drop this branch.
     |- Try 11 - 6 = 5. Evaluate 5 != 12, drop this branch.
     |- Try 11 * 6 = 66. Evaluate 66 != 12, drop this branch.
     |- Try 11 / 6 = 1.8. 1.8 is a decimal, drop this branch.
    |- Try 18 * 7 = 126. Add 126 to the number set. Current number set: [126, 6], target: 12, just two numbers left.
     |- Try 126 + 6 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 126 - 6 = 120. Evaluate 120 != 12, drop this branch.
     |- Try 126 * 6 = 756. Evaluate 756 != 12, drop this branch.
     |- Try 126 / 6 = 21. Evaluate 21 != 12, drop this branch.
    |- Try 18 / 7 = 2.6. 2.6 is a decimal, drop this branch.
   |- Pick two numbers (6, 18) (numbers left: [7]). Try possible operations.
    |- Try 18 + 6 = 24. Add 24 to the number set. Current number set: [24, 7], target: 12, just two numbers left.
     |- Try 24 + 7 = 31. Evaluate 31 != 12, drop this branch.
     |- Try 24 - 7 = 17. Evaluate 17 != 12, drop this branch.
     |- Try 24 * 7 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 24 / 7 = 3.4. 3.4 is a decimal, drop this branch.
    |- Try 18 - 6 = 12. Add 12 to the number set. Current number set: [12, 7], target: 12, just two numbers left.
     |- Try 12 + 7 = 19. Evaluate 19 != 12, drop this branch.
     |- Try 12 - 7 = 5. Evaluate 5 != 12, drop this branch.
     |- Try 12 * 7 = 84. Evaluate 84 != 12, drop this branch.
     |- Try 12 / 7 = 1.7. 1.7 is a decimal, drop this branch.
    |- Try 18 * 6 = 108. Add 108 to the number set. Current number set: [108, 7], target: 12, just two numbers left.
     |- Try 108 + 7 = 115. Evaluate 115 != 12, drop this branch.
     |- Try 108 - 7 = 101. Evaluate 101 != 12, drop this branch.
     |- Try 108 * 7 = 756. Evaluate 756 != 12, drop this branch.
     |- Try 108 / 7 = 15.4. 15.4 is a decimal, drop this branch.
    |- Try 18 / 6 = 3. Add 3 to the number set. Current number set: [3, 7], target: 12, just two numbers left.
     |- Try 7 + 3 = 10. Evaluate 10 != 12, drop this branch.
     |- Try 7 - 3 = 4. Evaluate 4 != 12, drop this branch.
     |- Try 7 * 3 = 21. Evaluate 21 != 12, drop this branch.
     |- Try 7 / 3 = 2.3. 2.3 is a decimal, drop this branch.
  |- Try 16 * 9 = 144. Add 144 to the number set. Current number set: [144, 6, 18], target: 12. Options for choosing two numbers: [(144, 6), (144, 18), (6, 18)].
   |- Pick two numbers (144, 6) (numbers left: [18]). Try possible operations.
    |- Try 144 + 6 = 150. Add 150 to the number set. Current number set: [150, 18], target: 12, just two numbers left.
     |- Try 150 + 18 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 150 - 18 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 150 * 18 = 2700. 2700 exceeds the maximum intermediate result, drop this branch.
     |- Try 150 / 18 = 8.3. 8.3 is a decimal, drop this branch.
    |- Try 144 - 6 = 138. Add 138 to the number set. Current number set: [138, 18], target: 12, just two numbers left.
     |- Try 138 + 18 = 156. Evaluate 156 != 12, drop this branch.
     |- Try 138 - 18 = 120. Evaluate 120 != 12, drop this branch.
     |- Try 138 * 18 = 2484. 2484 exceeds the maximum intermediate result, drop this branch.
     |- Try 138 / 18 = 7.7. 7.7 is a decimal, drop this branch.
    |- Try 144 * 6 = 864. Add 864 to the number set. Current number set: [864, 18], target: 12, just two numbers left.
     |- Try 864 + 18 = 882. Evaluate 882 != 12, drop this branch.
     |- Try 864 - 18 = 846. Evaluate 846 != 12, drop this branch.
     |- Try 864 * 18 = 15552. 15552 exceeds the maximum intermediate result, drop this branch.
     |- Try 864 / 18 = 48. Evaluate 48 != 12, drop this branch.
    |- Try 144 / 6 = 24. Add 24 to the number set. Current number set: [24, 18], target: 12, just two numbers left.
     |- Try 24 + 18 = 42. Evaluate 42 != 12, drop this branch.
     |- Try 24 - 18 = 6. Evaluate 6 != 12, drop this branch.
     |- Try 24 * 18 = 432. Evaluate 432 != 12, drop this branch.
     |- Try 24 / 18 = 1.3. 1.3 is a decimal, drop this branch.
   |- Pick two numbers (144, 18) (numbers left: [6]). Try possible operations.
    |- Try 144 + 18 = 162. Add 162 to the number set. Current number set: [162, 6], target: 12, just two numbers left.
     |- Try 162 + 6 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 162 - 6 = 156. Evaluate 156 != 12, drop this branch.
     |- Try 162 * 6 = 972. Evaluate 972 != 12, drop this branch.
     |- Try 162 / 6 = 27. Evaluate 27 != 12, drop this branch.
    |- Try 144 - 18 = 126. Add 126 to the number set. Current number set: [126, 6], target: 12, just two numbers left.
     |- Try 126 + 6 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 126 - 6 = 120. Evaluate 120 != 12, drop this branch.
     |- Try 126 * 6 = 756. Evaluate 756 != 12, drop this branch.
     |- Try 126 / 6 = 21. Evaluate 21 != 12, drop this branch.
    |- Try 144 * 18 = 2592. 2592 exceeds the maximum intermediate result, drop this branch.
    |- Try 144 / 18 = 8. Add 8 to the number set. Current number set: [8, 6], target: 12, just two numbers left.
     |- Try 8 + 6 = 14. Evaluate 14 != 12, drop this branch.
     |- Try 8 - 6 = 2. Evaluate 2 != 12, drop this branch.
     |- Try 8 * 6 = 48. Evaluate 48 != 12, drop this branch.
     |- Try 8 / 6 = 1.3. 1.3 is a decimal, drop this branch.
   |- Pick two numbers (6, 18) (numbers left: [144]). Try possible operations.
    |- Try 18 + 6 = 24. Add 24 to the number set. Current number set: [24, 144], target: 12, just two numbers left.
     |- Try 144 + 24 = 168. Evaluate 168 != 12, drop this branch.
     |- Try 144 - 24 = 120. Evaluate 120 != 12, drop this branch.
     |- Try 144 * 24 = 3456. 3456 exceeds the maximum intermediate result, drop this branch.
     |- Try 144 / 24 = 6. Evaluate 6 != 12, drop this branch.
    |- Try 18 - 6 = 12. Add 12 to the number set. Current number set: [12, 144], target: 12, just two numbers left.
     |- Try 144 + 12 = 156. Evaluate 156 != 12, drop this branch.
     |- Try 144 - 12 = 132. Evaluate 132 != 12, drop this branch.
     |- Try 144 * 12 = 1728. Evaluate 1728 != 12, drop this branch.
     |- Try 144 / 12 = 12. Evaluate 12 == 12, target found!

Now we have found the target, let's trace back the solution:
Final step: 144 / 12 = 12
The step before: 18 - 6 = 12
The first step: 16 * 9 = 144

Output the solution in the required format:
<Solution>
16 * 9 = 144
18 - 6 = 12
144 / 12 = 12
</Solution>

[Problem]
Now, solve the following problem. Note that:
- Please carefully read the approach and examples provided above, and follow them to solve the problem.
- Please ALWAYS include your search procedure (after # Search Procedure). The search procedure should follow the format of the examples provided above.
- Please mark your answer with <Solution> and </Solution> tags. The solution should be a sequence of three equations exactly following the format of the examples above, with no additional text in between.

Numbers: [28, 7, 44, 4]
Target: 27

# Search Procedure
Initial number set: [28, 7, 44, 4], target: 27. Options for choosing two numbers: [(28, 7), (28, 44), (28, 4), (7, 44), (7, 4), (44, 4)].
 |- Pick two numbers (28, 7) (numbers left: [44, 4]). Try possible operations.
  |- Try 28 + 7 = 35. Add 35 to the number set. Current number set: [35, 44, 4], target: 27. Options for choosing two numbers: [(35, 44), (35, 4), (44, 4)].
   |- Pick two numbers (35, 44) (numbers left: [4]). Try possible operations.
    |- Try 44 + 35 = 79. Add 79 to the number set. Current number set: [79, 4], target: 27, just two numbers left.
     |- Try 79 + 4 = 83. Evaluate 83 != 27, drop this branch.
     |- Try 79 - 4 = 75. Evaluate 75 != 27, drop this branch.
     |- Try 79 * 4 = 316. Evaluate 316 != 27, drop this branch.
     |- Try 79 / 4 = 19.8. 19.8 is a decimal, drop this branch.
    |- Try 44 - 35 = 9. Add 9 to the number set. Current number set: [9, 4], target: 27, just two numbers left.
     |- Try 9 + 4 = 13. Evaluate 13 != 27, drop this branch.
     |- Try 9 - 4 = 5. Evaluate 5 != 27, drop this branch.
     |- Try 9 * 4 = 36. Evaluate 36 != 27, drop this branch.
     |- Try 9 / 4 = 2.2. 2.2 is a decimal, drop this branch.
    |- Try 44 * 35 = 1540. Add 1540 to the number set. Current number set: [1540, 4], target: 27, just two numbers left.
     |- Try 1540 + 4 = 1544. Evaluate 1544 != 27, drop this branch.
     |- Try 1540 - 4 = 1536. Evaluate 1536 != 27, drop this branch.
     |- Try 1540 * 4 = 6160. 6160 exceeds the maximum intermediate result, drop this branch.
     |- Try 1540 / 4 = 385. Evaluate 385 != 27, drop this branch.
    |- Try 44 / 35 = 1.3. 1.3 is a decimal, drop this branch.
   |- Pick two numbers (35, 4) (numbers left: [44]). Try possible operations.
    |- Try 35 + 4 = 39. Add 39 to the number set. Current number set: [39, 44], target: 27, just two numbers left.
     |- Try 44 + 39 = 83. Evaluate 83 != 27, drop this branch.
     |- Try 44 - 39 = 5. Evaluate 5 != 27, drop this branch.
     |- Try 44 * 39 = 1716. Evaluate 1716 != 27, drop this branch.
     |- Try 44 / 39 = 1.1. 1.1 is a decimal, drop this branch.
    |- Try 35 - 4 = 31. Add 31 to the number set. Current number set: [31, 44], target: 27, just two numbers left.
     |- Try 44 + 31 = 75. Evaluate 75 != 27, drop this branch.
     |- Try 44 - 31 = 13. Evaluate 13 != 27, drop this branch.
     |- Try 44 * 31 = 1364. Evaluate 1364 != 27, drop this branch.
     |- Try 44 / 31 = 1.4. 1.4 is a decimal, drop this branch.
    |- Try 35 * 4 = 140. Add 140 to the number set. Current number set: [140, 44], target: 27, just two numbers left.
     |- Try 140 + 44 = 184. Evaluate 184 != 27, drop this branch.
     |- Try 140 - 44 = 96. Evaluate 96 != 27, drop this branch.
     |- Try 140 * 44 = 6160. 6160 exceeds the maximum intermediate result, drop this branch.
     |- Try 140 / 44 = 3.2. 3.2 is a decimal, drop this branch.
    |- Try 35 / 4 = 8.8. 8.8 is a decimal, drop this branch.
   |- Pick two numbers (44, 4) (numbers left: [35]). Try possible operations.
    |- Try 44 + 4 = 48. Add 48 to the number set. Current number set: [48, 35], target: 27, just two numbers left.
     |- Try 48 + 35 = 83. Evaluate 83 != 27, drop this branch.
     |- Try 48 - 35 = 13. Evaluate 13 != 27, drop this branch.
     |- Try 48 * 35 = 1680. Evaluate 1680 != 27, drop this branch.
     |- Try 48 / 35 = 1.4. 1.4 is a decimal, drop this branch.
    |- Try 44 - 4 = 40. Add 40 to the number set. Current number set: [40, 35], target: 27, just two numbers left.
     |- Try 40 + 35 = 75. Evaluate 75 != 27, drop this branch.
     |- Try 40 - 35 = 5. Evaluate 5 != 27, drop this branch.
     |- Try 40 * 35 = 1400. Evaluate 1400 != 27, drop this branch.
     |- Try 40 / 35 = 1.1. 1.1 is a decimal, drop this branch.
    |- Try 44 * 4 = 176. Add 176 to the number set. Current number set: [176, 35], target: 27, just two numbers left.
     |- Try 176 + 35 = 211. Evaluate 211 != 27, drop this branch.
     |- Try 176 - 35 = 141. Evaluate 141 != 27, drop this branch.
     |- Try 176 * 35 = 6160. 6160 exceeds the maximum intermediate result, drop this branch.
     |- Try 176 / 35 = 5.0. 5.0 is a decimal, drop this branch.
    |- Try 44 / 4 = 11. Add 11 to the number set. Current number set: [11, 35], target: 27, just two numbers left.
     |- Try 35 + 11 = 46. Evaluate 46 != 27, drop this branch.
     |- Try 35 - 11 = 24. Evaluate 24 != 27, drop this branch.
     |- Try 35 * 11 = 385. Evaluate 385 != 27, drop this branch.
     |- Try 35 / 11 = 3.2. 3.2 is a decimal, drop this branch.
  |- Try 28 - 7 = 21. Add 21 to the number set. Current number set: [21, 44, 4], target: 27. Options for choosing two numbers: [(21, 44), (21, 4), (44, 4)].
   |- Pick two numbers (21, 44) (numbers left: [4]). Try possible operations.
    |- Try 44 + 21 = 65. Add 65 to the number set. Current number set: [65, 4], target: 27, just two numbers left.
     |- Try 65 + 4 = 69. Evaluate 69 != 27, drop this branch.
     |- Try 65 - 4 = 61. Evaluate 61 != 27, drop this branch.
     |- Try 65 * 4 = 260. Evaluate 260 != 27, drop this branch.
     |- Try 65 / 4 = 16.2. 16.2 is a decimal, drop this branch.
    |- Try 44 - 21 = 23. Add 23 to the number set. Current number set: [23, 4], target: 27, just two numbers left.
     |- Try 23 + 4 = 27. Evaluate 27 == 27, target found!

Now we have found the target, let's trace back the solution:
Final step: 23 + 4 = 27
The step before: 44 - 21 = 23
The first step: 28 - 7 = 21

Output the solution in the required format:
<Solution>
28 - 7 = 21
44 - 21 = 23
23 + 4 = 27
</Solution>

Solution:
28 - 7 = 21
44 - 21 = 23
23 + 4 = 27