def min_difference(A, B):
    if A == 1 and B == 1:
        return 2
    if A > B:
        A, B = B, A
    if B <= 2 * A:
        result = (B - A) % 2
    else:
        result = B - 3 * A
    return max(0, result)  

A, B = map(int, input().split())
print(min_difference(A, B))