static void Main(string[] args)
        {
            yıl_2018 y1 = new yıl_2018();
            yıl_2019 y2 = new yıl_2019();

            Su  s1 = new Su();
            Cay c1 = new Cay();
            Et  e1 = new Et();

            s1.Kabulet(y1);
            c1.Kabulet(y1);
            e1.Kabulet(y1);


            Console.WriteLine("----------------------------------------------");

            s1.Kabulet(y2);
            c1.Kabulet(y2);
            e1.Kabulet(y2);

            Console.ReadLine();
        }
 public void visit(Cay cay)
 {
     Console.WriteLine("Çay vergi ücreti 2019  ");
 }