A, B = map(int,input().split())
A, B = '{:032b}'.format(A),'{:032b}'.format(B)

DP = [[0] * 2 for i in range(len(A)+1)]
DP[0][0]=1
for i in range(len(A)):
    if A[i] == '0' and B[i]=='0':
        DP[i+1][0]=DP[i][0]
        DP[i+1][1]=DP[i][1]
    if A[i] == '1' and B[i]=='0':
        print(0)
        exit()
    if A[i] == '0' and B[i]=='1':
        DP[i+1][0]*=0
        DP[i+1][1]+=1*DP[i][0]
        DP[i+1][1]+=2*DP[i][1]

    if A[i] == '1' and B[i]=='1':
        DP[i+1][0]=DP[i][0]
        DP[i+1][1]=DP[i][1]


print(DP[-1][0] + DP[-1][1])