using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        string input1 = "empty", sign = "empty" , input2 = "empty";

        float ans = 0f;

        while (input1 != "cancel" && input2 != "cancel" && sign  != "cancel")

        {

            Console.Write("Input 1 : ");

            input1 = Console.ReadLine();

            if (input1 == "cancel")

            {

                Console.WriteLine("\nGoodBye ...");

                break;

            }

            Console.Write("Input sign [+][-][*][/] : ");

            sign = Console.ReadLine();

            if (sign == "cancel")

            {

                Console.WriteLine("\nGoodBye ...");

                break;

            }

            Console.Write("Input 2 : ");

            input2 = Console.ReadLine();

            Console.Write("\n");

            if (input2 == "cancel")

            {

                Console.WriteLine("\nGoodBye ...");

                break;

            }

            if (input2 == "0" && sign == "/")

            {

                Console.WriteLine("Not divided By Zero \n");

                Console.WriteLine("////////////////////////////////\n");

            }

            else

            {

                if (char.Parse(sign) == '+')

                {

                    ans = float.Parse(input1) + float.Parse(input2);

                }

                else if (char.Parse(sign) == '-')

                {

                    ans = float.Parse(input1) - float.Parse(input2);

                }

                else if (char.Parse(sign) == '*')

                {

                    ans = float.Parse(input1) * float.Parse(input2);

                }

                else if (char.Parse(sign) == '/')

                {

                    ans = float.Parse(input1) / float.Parse(input2);

                }

                Console.WriteLine("{0} {1} {2} = {3:F}",input1,sign,input2,ans);

                Console.WriteLine("////////////////////////////////\n");

            }

        }

    }

}