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

conv_bit = lambda x: f"{x:b}"
zero_paddings = lambda x: f"{x:032}"

bitA = zero_paddings(int(conv_bit(A)))
bitB = zero_paddings(int(conv_bit(B)))

ans = 1
for a, b in zip(bitA, bitB):
    if a == b:
        continue
    elif a == "1":
        ans *= 0
    else:
        ans *= 2

print(ans if ans <= 1 else ans // 2)