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;
using System.Collections.Generic;

namespace program
{
    class Program
    {
        static void Main()
        {
          int[] a = Input.ScanIntArray();
          Console.WriteLine(a[1]%a[0]==0 ? a[0]+a[1]:a[1]-a[0]);
        }
    }

    static class Input
    {
        static public int ScanInt() { return int.Parse(Console.ReadLine()); }
        static public uint ScanUint() { return uint.Parse(Console.ReadLine()); }
        static public double ScanDouble() { return double.Parse(Console.ReadLine()); }
        static public long ScanLong() { return long.Parse(Console.ReadLine()); }
        static public ulong ScanUlong() { return ulong.Parse(Console.ReadLine()); }
        static public int[] ScanIntArray() { return Console.ReadLine().Split(' ').Select(x => int.Parse(x)).ToArray(); }
        static public uint[] ScanUintArray() { return Console.ReadLine().Split(' ').Select(x => uint.Parse(x)).ToArray(); }
        static public double[] ScanDoubleArray() { return Console.ReadLine().Split(' ').Select(x => double.Parse(x)).ToArray(); }
        static public long[] ScanLongArray() { return Console.ReadLine().Split(' ').Select(x => long.Parse(x)).ToArray(); }
        static public ulong[] ScanUlongArray() { return Console.ReadLine().Split(' ').Select(x => ulong.Parse(x)).ToArray(); }

        static public string ScanStr() { return Console.ReadLine(); }
        static public string[] ScanStrArray() { return ScanStr().Split(' '); }
    }

    static class MyMath
    {
        public static int GCD(int a, int b)
        {
            Func<int, int, int> gcd = null;
            gcd = (x, y) => y == 0 ? x : gcd(y, x % y);
            return a > b ? gcd(a, b) : gcd(b, a);
        }
        public static ulong GCD(ulong a, ulong b)
        {
            Func<ulong, ulong, ulong> gcd = null;
            gcd = (x, y) => y == 0 ? x : gcd(y, x % y);
            return a > b ? gcd(a, b) : gcd(b, a);
        }
        public static int LCM(int a, int b)
        {
            return a * b / GCD(a, b);
        }
        public static ulong LCM(ulong a, ulong b)
        {
            return a * b / GCD(a, b);
        }
    }
}