what is the minimum cost of the total hospital to include a drug called neomycin-polymyxin-gramicidin?
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 = 'neomycin-polymyxin-gramicidin' ) group by cost.hadm_id ) as t1