static void Main(string[] args)
        {
            Employee[] E = new Employee[4];   //Array of objects
            E[0] = new Employee();
            E[1] = new PartTimeEmployee();
            E[2] = new FullTimeEmployee();
            E[3] = new TemporaryEmployee();

            foreach (Employee e in E)
            {
                e.PrintFullName();
            }
            Console.ReadKey();
        }