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

if (A & B) != A:
    print(0)
else:
    k = 0
    for i in range(31):
        a_bit = (A >> i) & 1
        b_bit = (B >> i) & 1
        if a_bit == 0 and b_bit == 1:
            k += 1
    if k == 0:
        print(1 if A == B else 0)
    else:
        print(2 ** (k - 1))