import sys
input = lambda: sys.stdin.readline().rstrip()


def solve():
    a, b = map(int, input().split())  
    ans = 1
    ok = True
    for i in range(0, 30):
        if((a & (1 << i)) & (b & (1 << i))):
            ans *= 2
        if((a & (1 << i)) == 1 and (b & (1 << i)) == 0):
            ok = False
    if(ok):
        print(ans)
    else:
        print(0)

t = 1
# t = int(input())
for _ in range(t):
    solve()