01. Computer Store

using System;

namespace _01._Computer_Store
{
  class Program
  {
    static void Main (string[]args)
    {
      string partPrice = Console.ReadLine ();
      double currentPrice = 0;
      double totalPrice = 0;
      double discont = 0;
      while (partPrice != "regular")
    {
      if (partPrice == "special")
        {
          discont = totalPrice * 0.12;
          break;
        }

      currentPrice = double.Parse (partPrice);

      if (currentPrice < 0)
        {
          Console.WriteLine ("Invalid price!");
          currentPrice = 0;
        }
      totalPrice += currentPrice;
      partPrice = Console.ReadLine();

    }
      double priceWithTax = (totalPrice*1.2) - discont;
      if (priceWithTax == 0)
    {
      Console.WriteLine ("Invalid order!");
    }
      else
    {
      Console.WriteLine ("Congratulations you've just bought a new computer!");
      Console.WriteLine ($"Price without taxes: {totalPrice:f2}$");
      Console.WriteLine ($"Taxes: {(totalPrice*0.2):f2}$");
      Console.WriteLine ($"-----------");
      Console.WriteLine ($"Total price: {priceWithTax:f2}$");
    }
    }
  }
}