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 sc = new Scanner(System.in);
		
		int a = sc.nextInt();
		int b = sc.nextInt();
		
		sc.close();
		
		int[] arr = {1,2,3};
		
		for(int i : arr)
		{
			if(i == a || i == b)
			{
				
			}
			else
			{
				System.out.println(i);
			}
		}
	}
}
