Fito is doing Math homework. It turns out that the task he has to solve is really easy. However, he would like to write a program that computes the answer automatically. He knows that the teacher might ask the students to solve thousands of them. Since Fito is new to programming, he needs your help! Write a program that receives two positive integers $A$ and $B$. If $A$ is a divisor of $B$, the program should print $A + B$; otherwise, it should print $B − A$. This is Fito's math homework.
Input
The only line of input contains the two integers $A$ ($1\leq A \leq 20$) and $B$ ($1\leq B \leq 20$)
Output
If $A$ is a divisor of $B$, print $A + B$; otherwise, print $B − A$.
Sample test(s)
Input
4 12
Output
16
Input
8 20
Output
12
Input
1 1
Output
2