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: Runtime Error)

using System;

class Program
{
	public static void Main(string[] args)
	{
		int A, B, C = 0;
		Console.WriteLine("Aの値を入力してください");
		A = int.Parse(Console.ReadLine());
		Console.WriteLine("Bの値を入力してください");
		B = int.Parse(Console.ReadLine());

		if (1 <= A && A <= 20 && 1 <= B && B <= 20)
		{
			if (A <= B)
			{
				if (B % A == 0)
				{
					C = A + B;
				}

				else
				{
					C = B - A;
				}

			}
			Console.WriteLine("答えは" + C + "です");
		}
		else 
		{
			Console.WriteLine("入力対象外です");
		}
	}
}