a, b, c, x, y = 1500, 2000, 1600, 3, 2
#na, nb, nc = x, y, 0
mx = 10**18
for i in range(0, (x+y+1)):
  if i%2==1: continue
  total = a*(x-i//2) + b*(y-i//2) + c*i
  if total<mx:
    mx=total

print(mx)