static void Main(string[] args) { // ILector lector; Professor professor = new Professor("Ivan Ivanovich"); ICourse cours = professor.CreateCourse("ASP.NET.MVC"); AllCourses electives = new AllCourses(); electives.AddCourse(cours); Student student = new Student("Petya"); student.Subscribe(cours); cours.StartCours(); cours.FinishedCours(); Console.ReadKey(); }