static void Main(string[] args)
{
Person vanya = new Person("Vanya");
Person petya = new Person("Petya");
Person borya = new Person("Borya");
vanya.ComeToOffice += petya.OfficeMessage(Show_Message);
petya.ComeToOffice += new Person.OfficeMessage(Show_Message);
borya.ComeToOffice += new Person.OfficeMessage(Show_Message);
vanya.LeaveOffice += new Person.OfficeMessage(Show_Message);
petya.LeaveOffice += new Person.OfficeMessage(Show_Message);
borya.LeaveOffice += new Person.OfficeMessage(Show_Message);
vanya.Greet(petya, DateTime.Now);
petya.Greet(petya, DateTime.Now);
borya.Greet(petya, DateTime.Now);
Console.ReadKey();
}