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

public class Main {
	public static void main(String args[]) {
		java.util.Scanner sc = new java.util.Scanner(System.in);
		int A = sc.nextInt();
		int B = sc.nextInt();

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


	}
}