101180: [AtCoder]ABC118 A - B +/- A

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 $1$.