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 C++14 (GCC 5.4.1) (judge verdict: Accepted)

//{{{
#include <bits/stdc++.h>
using namespace std;
#define repX(a,b,child,x,...) x
#define repN(a) repX a
#define rep(...) repN((__VA_ARGS__,rep3,rep2,loop))(__VA_ARGS__)
#define rrep(...) repN((__VA_ARGS__,rrep3,rrep2))(__VA_ARGS__)
#define loop(n) rep2(i_,n)
#define rep2(i,n) rep3(i,0,n)
#define rep3(i,begin,end) for(int i=(int)(begin),i##_end=(int)(end);i<i##_end;++i)
#define rrep2(i,n) rrep3(i,n,0)
#define rrep3(i,begin,end) for(int i=(int)(begin-1),i##_end=(int)(end);i>=i##_end;--i)
#define foreach(x,a) for(auto&x:a)
using ll=long long;
const ll mod=(ll)1e9+7;
//}}}

int main(){
  int a, b;
  cin >> a >> b;
  int ans = 0;
  if(b % a == 0){
    ans = b + a;
  }else{
    ans = b - a;
  }
  cout << ans << endl;
  return 0;
}