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.

Examples

Input

3
1


Output

2


Input

1
2


Output

3
import java.util.*; 

class Main{
public static void main(String[] args){
	Scanner sc=new Scanner(System.in);
        int n=sc.nextInt();
        int m=sc.nextInt();
  
  int ans=6-n-m;
	
    
    System.out.println(ans);
    }
}
