Problem:
Score: 100 points

Problem Statement

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.

Sample Input 1

3
1

Sample Output 1

2

When we know 3 and 1 are both wrong, the correct choice is 2.

Sample Input 2

1
2

Sample Output 2

3

Solution in PHP7 (7.0.15) (judge verdict: Accepted)

<?php
/*dskhbfjkhs*/
$server = "php://stdin";
$handle = fopen($server, "r");
$t = trim(fgets($handle));
$s = trim(fgets($handle));
$m=[];
$m[$t]=1;
$m[$s]=1;
if(isset($m[1]) && isset($m[2]))
{
    echo '3'."\n";
}else if(isset($m[1]) && isset($m[3]))
{
    echo '2'."\n";
}else
{
    echo '1'."\n";
}


?>