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 != 1)) {
				System.out.println(1);
			}else if((A != 2) && (B != 2)) {
				System.out.println(2);
			}else {
				System.out.println(3);
			}
			
}
}