public static void Run()
        {
            Console.Clear();

            Child1 c1 = new Child1("C1", 20);
            Child2 c2 = new Child2();

            c1.Output();
            c2.Output();

            c1.Child_1_Special();
            c2.Child_2_Special();

            Exit(c1, c2);
        }
 private static void Exit(Child1 c1, Child2 c2)
 {
     c1 = null;
     c2 = null;
 }