a, b = map(int, input().split())
t = min(a, b) * 2
f = a + b - t
cnt = min(a, b)
if t < f:
    print(abs(t - f))
else:
    tmp = abs(t - f)
    while abs((t - 1) - (f + 1)) < tmp and 0 <= t - 1 and 0 < cnt:
        cnt -= 1
        t, f = t - 1, f + 1
        tmp = abs((t - 1) - (f + 1))
    print(tmp)