instruction: when were patient 010-1155 first prescribed for warfarin sodium 5 mg po tabs and potassium chloride at the same time in this month?
response: SELECT t1.drugstarttime FROM (SELECT patient.uniquepid, medication.drugstarttime FROM medication JOIN patient ON medication.patientunitstayid = patient.patientunitstayid WHERE medication.drugname = 'warfarin sodium 5 mg po tabs' AND patient.uniquepid = '010-1155' AND DATETIME(medication.drugstarttime, 'start of month') = DATETIME(CURRENT_TIME(), 'start of month', '-0 month')) AS t1 JOIN (SELECT patient.uniquepid, medication.drugstarttime FROM medication JOIN patient ON medication.patientunitstayid = patient.patientunitstayid WHERE medication.drugname = 'potassium chloride' AND patient.uniquepid = '010-1155' AND DATETIME(medication.drugstarttime, 'start of month') = DATETIME(CURRENT_TIME(), 'start of month', '-0 month')) AS t2 ON t1.uniquepid = t2.uniquepid WHERE DATETIME(t1.drugstarttime) = DATETIME(t2.drugstarttime) ORDER BY t1.drugstarttime LIMIT 1