c,d=gets.split.map(&:to_f)
tmp1=5 * c - 2 * d
tmp2=3 * d - c
ca=tmp1*3
cb=tmp2*2
da=tmp1
db=tmp2*5
p [4000 * [ca,da * 3].min / 3, 1400 * [5 * cb, 2 * db].min, (4000 * tmp1 + 14000 * tmp2)].max / 13