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)

//header{{{
#include<bits/stdc++.h>
  
using namespace std;
 
#define rep(i,n) for(int i=0;i<(n);++i)
#define reps(i,n) for(int i=1;i<=(n);++i)
#define all(x) (x).begin(),(x).end()
#define setout(n,x) setw(n+1) << setfill(x)
#define Fixed fixed << setprecision(10)
#define int int64_t
using pii = pair<int,int>;
constexpr int INF  = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr int mod = 1e9+7; 

template <class A, class B> inline bool chmax(A &a, const B &b) { return b > a && (a = b, true); }
template <class A, class B> inline bool chmin(A &a, const B &b) { return b < a && (a = b, true); }

template <class T> using min_heap = priority_queue<T,vector<T>,greater<T> >;
template <class T> using max_heap = priority_queue<T>;
  
int gcd(int a,int b){ return b ? gcd(b,a % b) : a;}
int lcm(int a,int b){ return a / gcd(a,b) * b;}
//}}}

signed main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
    vector<bool> v(5);
    int a,b;
    cin >> a >> b;
    v[a] = true;
    v[b] = true;
    if(!v[1]) cout << 1 << '\n';
    else if(!v[2]) cout << 2 << '\n';
    else cout << 3 << '\n';
	return 0;
}