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: Accepted)

program aba
  implicit none
  integer :: a, b
  read(*,*) a, b
  if (mod(b,a) .eq. 0) then
     write(*,'(i0)') a+b
  else
     write(*,'(i0)') b-a
  end if
  stop
end program aba