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 <iostream>
#include <vector>
#include <string>
#include <cstring>
#include <map>
#include <list>
#include <set>
#include <stack>
#include <deque>
#include <queue>
#include <cmath>
#include <algorithm>
#include <utility>
#include <functional>
#include <random>
#include <fstream>
#include <time.h>
// #define int long long
#define debug(x) cerr << #x << " = " << x << endl
#define FOR(i,a,b) for(int i = (a); i < (b); i++)
#define rep(i,n) for(int i = 0; i < (n); i++)
#define repr(i,n) for(int i = (n); i > -1; i--)
using namespace std;
typedef long long ll;
typedef pair<int, int> P;
const int MOD = 1000000007;
const ll LINF = 1e18;
const double EPS = 1e-9;


signed main() {
  cin.tie(0);
  ios::sync_with_stdio(false);

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

  return 0;
}