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);
		// 整数の入力
		int n1 = sc.nextInt();
		int n2 = sc.nextInt();
		int res = 0;
		for(int i=1;i<=3;i++) {
			if(i != n1 && i!= n2) {
				res = i;
				break;
			}
		}
		// 出力
		System.out.println(res);

		//scclose
		sc.close();
	}

}
