Problem:
Score : 100 points

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.

Solution in Python (3.4.3) (judge verdict: Runtime Error)

list1 = [int(a) for a in input().split()]
list1_0 = list1[0] #AB
list1_1 = list1[1] #BC
list1_2 = list1[2] #CA

if (list1_0 * list1_1 // 2) > 1:
    print(list1_0 * list1_1 // 2)
else:
    print(list1)