from sys import stdin


def main():
    input = lambda: stdin.readline()[:-1]
    A, B = map(int, input().split())

    if A & B != A:
        print(0)
        return

    a, i, zero = A, 0, 0
    while a > 0:
        if not A & 1 << i:
            zero += 1
        a //= 2
        i += 1
    print(2 ** (zero - 1))


main()