// Implement the data structure linked list.
public static void Main()
{
var linkedList = new LinkedList<string>();
linkedList.AddFirst("first");
linkedList.AddLast("second");
Console.WriteLine(string.Join(", ", linkedList));
linkedList.Clear();
linkedList.AddLast("second");
linkedList.AddFirst("first");
Console.WriteLine(string.Join(", ", linkedList));
string value = "first";
Console.WriteLine("List contains \"{0}\": {1}", value, linkedList.Contains(value));
Console.WriteLine("List contains {0} item(s)", linkedList.Count);
var item = linkedList.Find("second");
Console.WriteLine(item);
linkedList.Remove("first");
Console.WriteLine(string.Join(", ", linkedList));
linkedList.Remove("second");
Console.WriteLine("List contains {0} item(s): {1}", linkedList.Count, string.Join(", ", linkedList));
linkedList.AddFirst("second");
linkedList.AddFirst("first");
linkedList.AddLast("third");
Console.WriteLine(string.Join(", ", linkedList));
linkedList.Remove("second");
Console.WriteLine(string.Join(", ", linkedList));
}