using System;

public class Program

{

    public static void Main()

    {

        TestSwitch(10,20,'+');

    }

    public static void TestSwitch (int a, int b, char sign)     

    {   

        int result;

        switch(sign)

        {

            case '+':

                result= a + b;

                break;

            case '-':

                result= a - b;

                break;

            case '*':

                result= a * b;

                break;

            case '/':

                result= a / b;

                break;

            default:

                Console.WriteLine ("Unknown operator or sign");

                return;

        }

        Console.WriteLine ("result:{0}",result);

        return;

    }

}