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(Et et)
{
Console.WriteLine("et vergi ücreti 2019");
}