what has been the number of times patient 59486 has visited the icu on their first hospital encounter?
select count( distinct icustays.icustay_id ) from icustays where icustays.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 59486 and admissions.dischtime is not null order by admissions.admittime asc limit 1 )