what's the total amount of output patient 64519 had on 07/17/2104?
select sum(outputevents.value) from outputevents where outputevents.icustay_id in ( select icustays.icustay_id from icustays where icustays.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 64519 ) ) and strftime('%y-%m-%d',outputevents.charttime) = '2104-07-17'