using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading;
using System.Threading.Tasks;

namespace Test
{
    class Program
    {
        public static Int32 Height;
        public static Int32 Base;
        public static Int32 Result;

        public static bool isCalculating;

        static void Main()
        {
            string UserInput = ""; //This string will be used for information inputted by a user.

            Console.Clear(); //Clears the console.
            Console.WriteLine("Input The Height:"); //Writes in the console.
            UserInput = Console.ReadLine(); //Updates the user input string with what the user put into the console.
            if (Regex.IsMatch(UserInput, @"^[0-9]*$")) //Uses Regex to check if the user input is a number.
            {
                Height = Convert .ToInt32(UserInput); //Converts the user input into a integer.
                Console.WriteLine("Input The Base:"); //Writes in the console.
                UserInput = Console.ReadLine(); //Updates the user input string with what the user put into the console.
                if (Regex.IsMatch(UserInput, @"^[0-9]*$")) //Uses Regex to check if the user input is a number.
                {
                    Base = Convert.ToInt32(UserInput); //Converts the user input into a integer.
                    DoMath(); //Goto DoMath.
                }
                else
                {
                    Console.Clear(); //Clears the console.
                    Console.WriteLine("Please enter a number."); //Writes in the console.
                    Thread.Sleep(1000); //Sleeps the current tread.
                    Main(); //Goto Main.
                }
            }
            else
            {
                Console.Clear(); //Clears the console.
                Console.WriteLine("Please enter a number."); //Writes in the console.
                Thread.Sleep(1000); //Sleeps the current tread.
                Main(); //Goto Main.
            }
        }

        static void DoMath()
        {
            isCalculating = true; //Sets isCalculating to true.
            Thread t = new Thread(Calculating);
            t.Start();

            Thread.Sleep(1000); //Sleeps the current tread.
            Result = Height * Base / 2; //Does the maths.
            isCalculating = false; //Sets isCalculating to false.
            Thread.Sleep(100); //Sleeps the current tread.

            Console.Clear(); //Clears the console.
            Console.WriteLine("Your result is: " + Result); //Writes in the console.
            Console.ReadLine(); //Waits.
        }

        static void Calculating()
        {
            do //Loops while isCalculating is true.
            {
                Console.WriteLine("Calculating."); //Writes in the console.
                Thread.Sleep(100); //Sleeps the current tread.
                Console.Clear(); //Clears the console.
                Console.WriteLine("Calculating..");
                Thread.Sleep(100); //Sleeps the current tread.
                Console.Clear(); //Clears the console.
                Console.WriteLine("Calculating...");
                Thread.Sleep(100); //Sleeps the current tread.
                Console.Clear(); //Clears the console.
            } while (isCalculating is true);
        }
    }
}