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 ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORTASC(c) sort((c).begin(),(c).end())
#define SORTDESC(c,t) sort((c).begin(),(c).end(), std::greater<t>());
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)
#define VMAX(a) *max_element(ALL(a))
#define VMIN(a) *min_element(ALL(a))
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

const double PI  = acos(-1.0);

using ll = long long;
using namespace std;

int main() {
    ll a, b;
    ll answers[] = {1, 2, 3};

    cin >> a >> b;

    REP(i, 3){
        if (answers[i] != a && answers[i] != b){
            cout << answers[i] << endl;
            break;
        }
    }

    return 0;
}