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-----
4 12

-----Sample Output-----
16

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

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