static void Main() { TickTock time = new TickTock(); TooLate die = null; Stepan stepan = null; bool wannaBreak = false; while (true) { Console.WriteLine(menu); string response = Console.ReadLine(); int result; if (int.TryParse(response, out result) && result >= 1 && result <= 6) { switch (result) { case 1: Console.WriteLine("Enter time in milliseconds"); string responsedTime = Console.ReadLine(); int resultTime; if (int.TryParse(responsedTime, out resultTime)) { time.SetTheFinalCountDown(resultTime); } else { Console.WriteLine("Bad decision!"); } break; case 2: die = new TooLate(time); break; case 3: die?.Unregister(time); break; case 4: stepan = new Stepan(time); break; case 5: stepan?.Unregister(time); break; case 6: wannaBreak = true; break; } if (wannaBreak) { break; } } else { Console.WriteLine("Bad decision!"); } } }