private static void Main(string[] args) { // read students var provider = GetStudentsProvider(); List <Student> students = provider.GetStudents(); var university = new University("CH.U.I."); // add students to university university.AddStudents(students); Console.WriteLine("List of all students:"); Console.WriteLine(string.Join(", ", students.Select(x => x.Name))); // create intership with minimal level of knowlenge for student var internship = new Internship("Interlink", university.GetAverageStudentsLevel()); internship.ApplyToInternship(students); Console.WriteLine("List of internship's students:"); Console.WriteLine(internship.GetStudents()); Console.ReadKey(); }