static void Main(string[] args)
{
DoublyLinkedList <string> doublyLinkedList = new DoublyLinkedList <string>();
string input = Console.ReadLine();
while (input == "end")
{
doublyLinkedList.AddLast(input);
input = Console.ReadLine();
}
doublyLinkedList.Foreach(s => Console.WriteLine(s));
}
