static void Main(string[] args)
        {
            MyLinkedList <int> list = new MyLinkedList <int>();

            list.InsertAfter(11);
            list.InsertFirst(5);
            list.InsertFirst(6);
            list.InsertFirst(7);
            list.InsertAfter(1);
            list.InsertAfter(81);
            list.InsertAfter(10);
            list.InsertAfter(-1);

            list.DeleteFirst();
            list.DeleteAfter();


            Node <int> node = list.GetNode(7);

            if (node == null)
            {
                Console.WriteLine("Element is  apsent");
            }
            else
            {
                Console.WriteLine("Elemetn  is   present");
            }



            Console.WriteLine("Lenght =  {0}", list.length);



            Console.ReadKey();
        }