static void Main(string[] args) { while (true) { IOservice.ShowMessage ( "1 - TaskOne (conversion from grams)\n" + "2 - TaskTwo (converting bytes to kilo, mega, Giga)\n" + "3 - TaskThree (Centimeters to meters and kilometers)\n" + "4 - TaskFour (Swap values of variables without using an additional variable)\n" + "5 - TaskFive (the ratio of the cost of 1 kg of candy to 1 kg of gelatine)\n" + "exit - Exit the program" ); string command = IOservice.GetUserInputStr(); switch (command) { case "1": Task1.StartTask(); break; case "2": Task2.StartTask(); break; case "3": Task3.StartTask(); break; case "4": Task4.StartTask(); break; case "5": Task5.StartTask(); break; case "exit": return; default: IOservice.ShowMessage("Unknown command"); break; } } }