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 $B - A$.