C, D = map(int, input().split())
if 35 * C <= 14 * D:
    print(7000 * C)
elif 84 * D < 28 * C:
    print(4000 * D)
else:
    x = (140 * C - 56 * D) / 91
    y = (84 * D - 28 * C) / 52
    print(1000 * x + 2000 * y)