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.*;

class Main{
 public static void main(String args[]){
   Scanner scn = new Scanner(System.in);
   String a = scn.nextLine();
   String b = scn.nextLine();
   List<String> li = new ArrayList<String>();
   li.add("1");
   li.add("2");
   li.add("3");
   li.remove(a);
   li.remove(b);
   System.out.println(Integer.parseInt(li.get(0)));
 }
}