static void Main(string[] args) { ObjectStructure list = new ObjectStructure(); list.AddEmployee(new FulltimeEmployee("Mike", 2000)); list.AddEmployee(new FulltimeEmployee("Tony", 3000)); list.AddEmployee(new ParttimeEmployee("Nancen", 800)); list.AddEmployee(new ParttimeEmployee("Bibo", 500)); FinanceVisitor fVisitor = new FinanceVisitor(); HrVisitor hVisitor = new HrVisitor(); list.Accept(fVisitor); list.Accept(hVisitor); Console.ReadKey(); }