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)

#include <bits/stdc++.h>
#define rep(i,a,b) for(int i = (a); i <= (b); i++)
#define rng(a) a.begin(), a.end()
#define ina(n,a) cin >> n; for(int i = 1; i <= n; i++) cin >> a[i]
#define sz(x) (int)(x).size()
#define se second
#define fi first
#define prev            coyhhhhhhyoc    
#define next          sdNNNmNNNNNNNmds  
#define y0           hNNNNy_yNNNNNN_sNh
#define y1          mNNNNNdtdNNNNNNtsNNm
#define yn          mNNNNNNNNy___smNNNms
#define tm            oooooosyysooooot 
#define read               tyhyt        
#define rank              ytmNmo         
#define index              yyy
#define pb push_back
#define pcnt __builtin_popcountll
#define rrep(i,a,b) for(int i = (b); i >= (a); i--)
#define rall(x,a) for(auto x : a)
#define MOD 1000000007
#define endl "\n"
typedef long long ll;
using namespace std;

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int x, y;
    cin >> x >> y;
    cout << (x ^ y) << endl;
    return 0;
}