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);
			//there's only 1 2 and 3
			// sum = 6;
			int a=sc.nextInt();
			int b=sc.nextInt(); 
			
			
			int sum=a+b;
			
			System.out.println(6-sum);
}
	
	}