"""
[24606: Double Password](https://www.acmicpc.net/problem/24606)
Tier: Bronze 4
Category: 구현
"""
def solution():
a = input()
b = input()
ans = 1
for i in range(4):
if a[i] != b[i]:
ans *= 2
return ans
if __name__ == '__main__':
print(solution())