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 <iostream>
#include <string>
#include <vector>
#include <queue>
#include <algorithm>
#include <map>
#include <math.h>
#include <numeric>
#include <set>
#include <unordered_map>
#include <unordered_set>

using namespace std;

int main()
{
  set<int> s;
  s.insert(1);
  s.insert(2);
  s.insert(3);
  
  int a,b;
  
  cin>>a>>b;
  s.erase(a);
  s.erase(b);
  
  cout<<*s.begin()<<endl;
  
  return 0;
}