public static void ToBookARoom(Hotel hotel, Guest guest) { int[] rooms = null; string category = ""; Console.WriteLine("What type of room would you like to book?"); Console.WriteLine("1 Standart"); Console.WriteLine("2 Medium"); Console.WriteLine("3 Lux"); category = Console.ReadLine(); switch (category) { case null: Console.WriteLine("Sorry you did something wrong."); break; case "1": rooms = Hotel.Standart; break; case "2": rooms = Hotel.Medium; break; case "3": rooms = Hotel.Lux; break; default: throw new Exception(); } Console.WriteLine("How many days are you planning to stay?"); int day = Convert.ToInt32(Console.ReadLine()); if (day <= 0) { throw new Exception(); } decimal topay = day * hotel[rooms[0]].Price; Console.WriteLine($"To pay: {topay}."); Console.ReadKey(); Console.WriteLine("*money*"); Console.ReadKey(); foreach (int r in rooms) { if (guest.ToBook(day, hotel[r])) { Hotel.Booked.Add(r, guest); break; } } }