static void Main(string[] args) { Student ob1 = new Student("123", "King", 3.25); Student ob2 = new Student("125", "Queen", 3.5); Student.AddStudent(ob1); Student.AddStudent(ob2); Student.PrintAll(); School ob3 = new School(); ob3.Add("123", "King"); ob3.Add("125", "Queen"); ob3.Update("129", 3.5); ob3.Remove("129"); ob3.Remove("123"); Console.ReadKey(); }