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>
typedef long long ll;
using namespace std;
const int N =2e5+10 , M = 5e5+10, OO = 0x3f3f3f3f ,  MOD = 1e9+7;
const double EPS = 1e-3;
#define M_PI 3.14159265358979323846
#define clr(arr,val) memset(arr , val , sizeof (arr))
#define loop(i,n) for(int i = 0;i < int(n);i++)
#define rloop(i,n) for(int i = int(n)-1;i >= 0;i--)
#define range(i,a,b) for(int i = int(a);i <= int(b);i++)
#define pb push_back
#define F first
#define S second
#define all(v) ((v).begin()) , ((v).end())
#define sz(v)  ((int)((v).size()))
typedef pair <int,int> pii ;
typedef vector < pii > vii ;
int dx[]={1,0,-1,0};int dy[]={0,1,0,-1}; //4 Direction
//int dx[]={1,1,0,-1,-1,-1,0,1};int dy[]={0,1,1,1,0,-1,-1,-1};//8 direction
//int dx[]={2,1,-1,-2,-2,-1,1,2};int dy[]={1,2,2,1,-1,-2,-2,-1};//Knight Direction
//int dx[6]={2,1,-1,-2,-1,1};int dy[6]={0,1,1,0,-1,-1}; //Hexagonal Direction
//freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);


int a,b;
int arr[5];

int main(){


    //ios_base::sync_with_stdio(0);
    //cin.tie(0);cout.tie(0);



	scanf("%d %d",&a,&b);
	arr[a] = 1;
	arr[b] = 1;
	for(int i = 1 ; i <= 3 ; ++i)
		if(arr[i] == 0)
			return printf("%d\n",i) , 0;



	

    

    return 0;
}