static void Main(string[] args) { First first = new First(); first.FirstMethod(); Second second = new Second(); second.SecondMethod(); FirstAndSecond firstandsecond = new FirstAndSecond(); firstandsecond.FirstMethod(); firstandsecond.SecondMethod(); FirstAndSecondClass firstandsecondclass = new FirstAndSecondClass(); firstandsecondclass.FirstMethod(); Console.ReadKey(); }