A,B = map(int,input().split())
N = A.bit_length()
M = B.bit_length()
bit1 = [0] * 30
bit2 = [0] * 30
for i in range(N):
    if A & (1 << i):
        bit1[i] = 1
for i in range(M):
    if B & (1 << i):
        bit2[i] = 1
cnt = 0
for i in range(30):
    if bit1[i] == 1 and bit2[i] == 0:
        print(0)
        exit()
    if bit1[i] == 0 and bit2[i] == 1:
        cnt += 1
print(pow(2, cnt))