Problem:
Score: 100 points

Problem Statement

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.

Sample Input 1

3
1

Sample Output 1

2

When we know 3 and 1 are both wrong, the correct choice is 2.

Sample Input 2

1
2

Sample Output 2

3

Solution in C++14 (GCC 5.4.1) (judge verdict: Accepted)

#define _USE_MATH_DEFINES
#include <iostream>
#include <string>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <cmath>
#include <algorithm>
#include <iomanip>
#include <climits>
using namespace std;
#define MOD int(1e9 + 7)
#define INF (long long)(1e18)

int main()
{
    cout.precision(18);
    
    long long A, B;
    vector<long long> a(3, 0);

    cin >> A >> B;
    a[A-1] = 1;
    a[B-1] = 1;

    for(long long i = 0; i < 3; i++){
      if(a[i] == 0){
        cout << i + 1 << endl;
        return 0;
      }
    }

    return 0;

}