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){
		try(Scanner sc = new Scanner(System.in)) {
		
			int[] ans = new int[3];
			
			ans[sc.nextInt() - 1 ]  = 1;
			ans[sc.nextInt() - 1 ] = 1;
			
			for(int i = 0 ; i < 3 ; i++ ) {
				if ( ans[i] == 0 ) {
					System.out.println(i+1);
				}
			}

		}
	}

}