A,B = map(int,input().split())
bit1 = [0] * 32
bit2 = [0] * 32
for i in range(32):
    if A & (1 << i):
        bit1[i] = 1
for i in range(32):
    if B & (1 << i):
        bit2[i] = 1
ans = 1
cnt = 1
for i in range(32):
    if bit1[i] == 1 and bit2[i] == 0:
        ans *= 0
    if bit1[i] == 0 and bit2[i] == 1:
        ans *= cnt
        cnt *= 2
print(ans)