#!/usr/bin/env python3
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 * (3*d - c)
if a < 0 or b < 0:
    a, b = 0, 0
print(max([ 1000*a0, 2000*b0, 1000*a + 2000*b ]))