tell me the difference in patient 269's red blood cells levels second measured on the last hospital visit compared to the first value measured on the last hospital visit?
CREATE TABLE d_labitems (
    row_id number,
    itemid number,
    label text
)

CREATE TABLE microbiologyevents (
    row_id number,
    subject_id number,
    hadm_id number,
    charttime time,
    spec_type_desc text,
    org_name text
)

CREATE TABLE d_icd_diagnoses (
    row_id number,
    icd9_code text,
    short_title text,
    long_title text
)

CREATE TABLE transfers (
    row_id number,
    subject_id number,
    hadm_id number,
    icustay_id number,
    eventtype text,
    careunit text,
    wardid number,
    intime time,
    outtime time
)

CREATE TABLE diagnoses_icd (
    row_id number,
    subject_id number,
    hadm_id number,
    icd9_code text,
    charttime time
)

CREATE TABLE d_items (
    row_id number,
    itemid number,
    label text,
    linksto text
)

CREATE TABLE labevents (
    row_id number,
    subject_id number,
    hadm_id number,
    itemid number,
    charttime time,
    valuenum number,
    valueuom text
)

CREATE TABLE patients (
    row_id number,
    subject_id number,
    gender text,
    dob time,
    dod time
)

CREATE TABLE outputevents (
    row_id number,
    subject_id number,
    hadm_id number,
    icustay_id number,
    charttime time,
    itemid number,
    value number
)

CREATE TABLE prescriptions (
    row_id number,
    subject_id number,
    hadm_id number,
    startdate time,
    enddate time,
    drug text,
    dose_val_rx text,
    dose_unit_rx text,
    route text
)

CREATE TABLE procedures_icd (
    row_id number,
    subject_id number,
    hadm_id number,
    icd9_code text,
    charttime time
)

CREATE TABLE chartevents (
    row_id number,
    subject_id number,
    hadm_id number,
    icustay_id number,
    itemid number,
    charttime time,
    valuenum number,
    valueuom text
)

CREATE TABLE inputevents_cv (
    row_id number,
    subject_id number,
    hadm_id number,
    icustay_id number,
    charttime time,
    itemid number,
    amount number
)

CREATE TABLE cost (
    row_id number,
    subject_id number,
    hadm_id number,
    event_type text,
    event_id number,
    chargetime time,
    cost number
)

CREATE TABLE icustays (
    row_id number,
    subject_id number,
    hadm_id number,
    icustay_id number,
    first_careunit text,
    last_careunit text,
    first_wardid number,
    last_wardid number,
    intime time,
    outtime time
)

CREATE TABLE admissions (
    row_id number,
    subject_id number,
    hadm_id number,
    admittime time,
    dischtime time,
    admission_type text,
    admission_location text,
    discharge_location text,
    insurance text,
    language text,
    marital_status text,
    ethnicity text,
    age number
)

CREATE TABLE d_icd_procedures (
    row_id number,
    icd9_code text,
    short_title text,
    long_title text
)
SELECT (SELECT labevents.valuenum FROM labevents WHERE labevents.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 269 AND NOT admissions.dischtime IS NULL ORDER BY admissions.admittime DESC LIMIT 1) AND labevents.itemid IN (SELECT d_labitems.itemid FROM d_labitems WHERE d_labitems.label = 'red blood cells') ORDER BY labevents.charttime LIMIT 1 OFFSET 1) - (SELECT labevents.valuenum FROM labevents WHERE labevents.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 269 AND NOT admissions.dischtime IS NULL ORDER BY admissions.admittime DESC LIMIT 1) AND labevents.itemid IN (SELECT d_labitems.itemid FROM d_labitems WHERE d_labitems.label = 'red blood cells') ORDER BY labevents.charttime LIMIT 1)
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: tell me the difference in patient 269's red blood cells levels second measured on the last hospital visit compared to the first value measured on the last hospital visit? ### Input: CREATE TABLE d_labitems (
    row_id number,
    itemid number,
    label text
)

CREATE TABLE microbiologyevents (
    row_id number,
    subject_id number,
    hadm_id number,
    charttime time,
    spec_type_desc text,
    org_name text
)

CREATE TABLE d_icd_diagnoses (
    row_id number,
    icd9_code text,
    short_title text,
    long_title text
)

CREATE TABLE transfers (
    row_id number,
    subject_id number,
    hadm_id number,
    icustay_id number,
    eventtype text,
    careunit text,
    wardid number,
    intime time,
    outtime time
)

CREATE TABLE diagnoses_icd (
    row_id number,
    subject_id number,
    hadm_id number,
    icd9_code text,
    charttime time
)

CREATE TABLE d_items (
    row_id number,
    itemid number,
    label text,
    linksto text
)

CREATE TABLE labevents (
    row_id number,
    subject_id number,
    hadm_id number,
    itemid number,
    charttime time,
    valuenum number,
    valueuom text
)

CREATE TABLE patients (
    row_id number,
    subject_id number,
    gender text,
    dob time,
    dod time
)

CREATE TABLE outputevents (
    row_id number,
    subject_id number,
    hadm_id number,
    icustay_id number,
    charttime time,
    itemid number,
    value number
)

CREATE TABLE prescriptions (
    row_id number,
    subject_id number,
    hadm_id number,
    startdate time,
    enddate time,
    drug text,
    dose_val_rx text,
    dose_unit_rx text,
    route text
)

CREATE TABLE procedures_icd (
    row_id number,
    subject_id number,
    hadm_id number,
    icd9_code text,
    charttime time
)

CREATE TABLE chartevents (
    row_id number,
    subject_id number,
    hadm_id number,
    icustay_id number,
    itemid number,
    charttime time,
    valuenum number,
    valueuom text
)

CREATE TABLE inputevents_cv (
    row_id number,
    subject_id number,
    hadm_id number,
    icustay_id number,
    charttime time,
    itemid number,
    amount number
)

CREATE TABLE cost (
    row_id number,
    subject_id number,
    hadm_id number,
    event_type text,
    event_id number,
    chargetime time,
    cost number
)

CREATE TABLE icustays (
    row_id number,
    subject_id number,
    hadm_id number,
    icustay_id number,
    first_careunit text,
    last_careunit text,
    first_wardid number,
    last_wardid number,
    intime time,
    outtime time
)

CREATE TABLE admissions (
    row_id number,
    subject_id number,
    hadm_id number,
    admittime time,
    dischtime time,
    admission_type text,
    admission_location text,
    discharge_location text,
    insurance text,
    language text,
    marital_status text,
    ethnicity text,
    age number
)

CREATE TABLE d_icd_procedures (
    row_id number,
    icd9_code text,
    short_title text,
    long_title text
) ### Response: SELECT (SELECT labevents.valuenum FROM labevents WHERE labevents.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 269 AND NOT admissions.dischtime IS NULL ORDER BY admissions.admittime DESC LIMIT 1) AND labevents.itemid IN (SELECT d_labitems.itemid FROM d_labitems WHERE d_labitems.label = 'red blood cells') ORDER BY labevents.charttime LIMIT 1 OFFSET 1) - (SELECT labevents.valuenum FROM labevents WHERE labevents.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 269 AND NOT admissions.dischtime IS NULL ORDER BY admissions.admittime DESC LIMIT 1) AND labevents.itemid IN (SELECT d_labitems.itemid FROM d_labitems WHERE d_labitems.label = 'red blood cells') ORDER BY labevents.charttime LIMIT 1)