c,d=[int(i) for i in input().split()]

x_kouten = 20*c/13 - 8*d/13
y_kouten = -7*c/13 + 21*d/13

if x_kouten>=0 and y_kouten>=0:
    z=1000*x_kouten + 2000*y_kouten
elif x_kouten>=0 and y_kouten<0:
    z=1000*4*d
elif x_kouten<0 and y_kouten>=0:
    z=2000*7*c/2