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.*;
import java.lang.*;
import java.io.*;

class Main
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Scanner io = new Scanner(System.in);
		int a = io.nextInt(), b = io.nextInt();
		if(a != 1 && b != 1) System.out.println(1);
		if(a != 2 && b != 2) System.out.println(2);
		if(a != 3 && b != 3) System.out.println(3);
	}
}