static void Main(string[] args)
        {
            Finance finance = new Finance();
            HR      hr      = new HR();

            var employees = new dynamic[] { new Ceo(), new Programmer(), new Accountant() };

            finance.CalculateSalaries(employees);
            hr.ShowIdCards(employees);

            Console.Read();
        }
        static void Main(string[] args)
        {
            Finance finance = new Finance();
            HR      hr      = new HR();

            List <IPayable> employees = new List <IPayable> {
                new Ceo(), new Programmer()
            };
            List <IVisitor> visitors = new List <IVisitor> {
                new Ceo(), new Programmer(), new Volunteer()
            };


            finance.CalculateSalaries(employees);
            hr.ShowIdCards(visitors);

            Console.Read();
        }