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# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Linq;

class Procon {
  public Procon () { }
  static void Main (string[] agrs) {
    new Procon ().Do ();
  }

  Scanner cin;

  public void Do () {
    cin = new Scanner ();
    int A = cin.nextInt ();
    int B = cin.nextInt ();

    if ((B % A) == 0) {
      Console.WriteLine (A + B);
      return;
    }

    Console.WriteLine (B - A);
    return;
  }
}

class Scanner {
  string[] s;
  int i;
  int max_i;

  public Scanner () {
    s = new string[0];
    max_i = 0;
    i = 0;
  }

  public string nextString () {
    if (i >= s.Length) {
      s = Console.ReadLine ().Split (' ');
      max_i = s.Length;
      i = 0;
      if (max_i == 0) {
        return "";
      }
      return s[i++];
    } else {
      return s[i++];
    }
  }

  public int nextInt () {
    return int.Parse (nextString ());
  }

  public long nextLong () {
    return long.Parse (nextString ());
  }

  public double nextDouble () {
    return double.Parse (nextString ());
  }

  public string[] arrayString () {
    return Console.ReadLine ().Split (' ');
  }

  public int[] arrayInt () {
    string[] str = Console.ReadLine ().Split (' ');
    int[] array = new int[str.Length];
    for (int i = 0; i < str.Length; i++) {
      array[i] = int.Parse (str[i]);
    }
    return array;
  }

  public long[] arrayLong () {
    string[] str = Console.ReadLine ().Split (' ');
    long[] array = new long[str.Length];
    for (int i = 0; i < str.Length; i++) {
      array[i] = long.Parse (str[i]);
    }
    return array;
  }

  public double[] arrayDouble () {
    string[] str = Console.ReadLine ().Split (' ');
    double[] array = new double[str.Length];
    for (int i = 0; i < str.Length; i++) {
      array[i] = double.Parse (str[i]);
    }
    return array;
  }
}