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

class Inputs
{
    public static function d()
    {
        fscanf(STDIN, '%d', $a);
        return $a;
    }
}

$a = Inputs::d();
$b = Inputs::d();
for ($i =1; $i <= 3; $i++) {
    if ($a !== $i && $b !== $i) {
        echo $i . PHP_EOL;
    }
}