instruction: calculate the duration of stay during patient 007-4322's first stay in the intensive care unit.
response: SELECT STRFTIME('%j', patient.unitdischargetime) - STRFTIME('%j', patient.unitadmittime) FROM patient WHERE patient.patienthealthsystemstayid IN (SELECT patient.patienthealthsystemstayid FROM patient WHERE patient.uniquepid = '007-4322') AND NOT patient.unitadmittime IS NULL ORDER BY patient.unitadmittime LIMIT 1