634B - XOR Equation - CodeForces Solution

s, x = [int(i) for i in input().split()]

d = s - x

if d % 2:
    print(0)
elif (d >> 1) & x:
    print(0)
else:
    count = 2**(bin(x).count('1'))
        if d == 0:
        count -= 2
    print(count)