static void Main(string[] args) { Subject subject = new Subject(); int Cont = 1; do { Console.WriteLine("Hello! \nWhat do you want to do?"); Console.WriteLine("(1) - Add new member"); Console.WriteLine("(2) - Remove a member"); Console.WriteLine("(3) - Add new product to the store"); int menyVal = Convert.ToInt32(Console.ReadLine()); Console.Clear(); switch (menyVal) { case 1: AddWho(); Console.Clear(); break; case 2: RemoveWho(); Console.Clear(); break; case 3: subject.Inventory++; break; case 4: Cont = 0; break; default: break; } } while (Cont == 1); void AddWho() { Console.WriteLine("What is the member's name? "); String memberName = Console.ReadLine(); Observer member = new Observer(memberName); subject.BecomeMember(member); } void RemoveWho() { int nummer = 0; foreach (var member in subject.Members) { nummer++; Console.WriteLine("(" + nummer + ")" + member.ObserverName); } Console.WriteLine("Who do you want to remove?"); int removeWho = Convert.ToInt32(Console.ReadLine()); subject.RemoveMember(subject.Members[removeWho - 1]); } }