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.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner scan= new Scanner(System.in);
		int n=3;
		int[] a= new int[2];
		int sum=0;
		for(int i=0;i<2;i++)
		{
			a[i]=scan.nextInt();
			sum+=a[i];
		}
		n=n*(n+1)/2;
		System.out.println(n-sum);
	}

}
