# coding: utf-8
# Your code here!
C,D=map(int,input().split())

a0 = min(C * 4/3, D * 4/1)
b0 = min(C * 7/2, D * 7/5)
a=4/13*(5*C-2*D)
b=7/13*(-C+3*D)

if a<0 or b<0:
    a,b=0,0

print(max(1000*a+2000*b,1000*a0,2000*b0))