Editorial for T-Shirts
Submitting an official solution before solving the problem yourself is a bannable offence.
We make the observation that every time we have a free T-shirt deal, we should redeem it for the most expensive T-shirt – that is, large if there are any, otherwise medium if there are any, otherwise small. An easy way to implement this is to put all T-shirts in sorted order inside a double-ended list and keep popping from both sides.
s,m,l = map(int,raw_input().split()) a,b,c = map(float,raw_input().split()) total = 0.0 costs =  for i in range(s): costs.append(a) for i in range(m): costs.append(b) for i in range(l): costs.append(c) count = 0 while costs: total += costs.pop(0) count += 1 if count % 3 ==0 and costs: costs.pop(-1) print format(total,".2f")