calculate how many times patient 7165 had the intake of sterile water po.
select count(*) from inputevents_cv where inputevents_cv.icustay_id in ( select icustays.icustay_id from icustays where icustays.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 7165 ) ) and inputevents_cv.itemid in ( select d_items.itemid from d_items where d_items.label = 'sterile water po' and d_items.linksto = 'inputevents_cv' )