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 Fortran (gfortran v4.8.4) (judge verdict: Wrong Answer)

program test
implicit none
integer::a,b,c,d

 
read*,a,b
 
c=mod(a,b)
 
if (c==0) then
d=a+b
else
d=b-a
end if
 
print*,d
 
end program test