what was the total amount of ostomy (output) output patient 96728 had on 06/30/2103?
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 = 96728 ) ) and outputevents.itemid in ( select d_items.itemid from d_items where d_items.label = 'ostomy (output)' and d_items.linksto = 'outputevents' ) and strftime('%y-%m-%d',outputevents.charttime) = '2103-06-30'