from math import prod

a, b = [f"{int(x):b}" for x in input().split()]
if len(a) > len(b):
    b = "0" * (len(a) - len(b)) + b
elif len(a) < len(b):
    a = "0" * (len(b) - len(a)) + a
ans = []
for ai, bi in zip(a, b):
    if ai == "0" and bi == "0":
        ans.append(1)
    elif ai == "1" and bi == "1":
        ans.append(1)
    elif ai == "1" and bi == "0":
        ans.append(0)
    elif ai == "0" and bi == "1":
        ans.append(2)

print(prod(ans) // 2)