what is the minimum cost of a hospital bill that includes a drug called loperamide hcl in 2101?
select min(t1.c1) from ( select sum(cost.cost) as c1 from cost where cost.hadm_id in ( select prescriptions.hadm_id from prescriptions where prescriptions.drug = 'loperamide hcl' ) and strftime('%y',cost.chargetime) = '2101' group by cost.hadm_id ) as t1