instruction: what was the last weight for patient 23070 during the last month?
response: SELECT chartevents.valuenum FROM chartevents WHERE chartevents.icustay_id IN (SELECT icustays.icustay_id FROM icustays WHERE icustays.hadm_id IN (SELECT admissions.hadm_id FROM admissions WHERE admissions.subject_id = 23070)) AND chartevents.itemid IN (SELECT d_items.itemid FROM d_items WHERE d_items.label = 'admit wt' AND d_items.linksto = 'chartevents') AND DATETIME(chartevents.charttime, 'start of month') = DATETIME(CURRENT_TIME(), 'start of month', '-1 month') ORDER BY chartevents.charttime DESC LIMIT 1