static void Main(string[] args)
        {
            int choice,
                dataType = ListElementTypeChoice();

            GenericLinkedList <int>    intList    = new GenericLinkedList <int>();
            GenericLinkedList <double> doubleList = new GenericLinkedList <double>();
            GenericLinkedList <string> stringList = new GenericLinkedList <string>();

            switch (dataType)
            {
            case 1:
                intList.CreateList();
                break;

            case 2:
                doubleList.CreateList();
                break;

            case 3:
                stringList.CreateList();
                break;
            }

            while (true)
            {
                choice = GetMenuChoice();

                if (choice is 12)
                {
                    return;
                }

                switch (dataType)
                {
                case 1:
                    AppOperations(intList, choice);
                    break;

                case 2:
                    AppOperations(doubleList, choice);
                    break;

                case 3:
                    AppOperations(stringList, choice);
                    break;
                }

                WriteLine();
            }
        }