Takahashi is solving quizzes. He has easily solved all but the last one.

The last quiz has three choices: 1, 2, and 3.

With his supernatural power, Takahashi has found out that the choices A and B are both wrong.

Print the correct choice for this problem.

Constraints

* Each of the numbers A and B is 1, 2, or 3.
* A and B are different.

Input

Input is given from Standard Input in the following format:


A
B


Output

Print the correct choice.

Examples

Input

3
1


Output

2


Input

1
2


Output

3
import sys
input = sys.stdin.readline
# sys.setrecursionlimit(100000)


def main():
    N = int(input())
    M = int(input())
    ans = [1, 2, 3]
    ans.remove(N)
    ans.remove(M)
    print(ans[0])


if __name__ == "__main__":
    main()