Problem Statement

You are given positive integers A and B.
If A is a divisor of B, print A + B; otherwise, print B - A.

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.

Constraints

• All values in input are integers.
• $1 \leq A \leq B \leq 20$

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.

见题面 Input 部分

见题面 Output 部分