Problem:
Score : 100 points

Problem Statement

You are given positive integers A and B.

If A is a divisor of B, print A + B; otherwise, print B - A.

Constraints

All values in input are integers.

1 \leq A \leq B \leq 20

Input

Input is given from Standard Input in the following format:

A B

Output

If A is a divisor of B, print A + B; otherwise, print B - A.

Sample Input 1

4 12

Sample Output 1

16

As 4 is a divisor of 12, 4 + 12 = 16 should be printed.

Sample Input 2

8 20

Sample Output 2

12

Sample Input 3

1 1

Sample Output 3

2

1 is a divisor of 1.

Solution in PHP (5.6.30) (judge verdict: Accepted)

<?php
$input = trim(fgets(STDIN));
$input = preg_split('/\s/', $input);

$a = intval($input[0]);
$b = intval($input[1]);

if($b % $a == 0){
    puts($a + $b);
}
else{
    puts($b - $a);

}

function puts($str = ""){
    echo $str, "\n";
}