static void TestEmployee2()
{
OfficialEmployee duc = new OfficialEmployee();
int salary = duc.Payroll(20);
Console.WriteLine($"Luong cua Duc = {salary}");
}
static void TestEmloyee()
{
OfficialEmployee duc = new OfficialEmployee();
duc.Id = 1;
duc.Name = "Ngo Anh Duc";
Console.WriteLine($"Luong cua { duc.Name} = ");
duc.Payroll();
UnofficialEmployee hoang = new UnofficialEmployee();
hoang.Id = 2;
hoang.Name = "Vuong Ngoc Hoang";
Console.WriteLine($"Luong cua {hoang.Name} = ");
hoang.Payroll();
}