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.*;

public class Main{

	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		int A = sc.nextInt();
		int B = sc.nextInt();
		
		if(A == 1 && B == 2 || A==2 && B==1){
			System.out.println(3);
		}else if(A ==1 && B == 3 || A == 3 && B ==1){
			System.out.println(2);
		}else{
		System.out.println(1);
	}
	}
}