public class Node
{
 public int Data { get; set; }
 public Node Next { get; set; }
 public Node(int data)
 {
   this.Data = data;
 }
}
public class Queue
{
 private Node _head;
 private Node _tail;
 private int _count = 0;
 public Queue() { }
 public void Enqueue(int data)
 {
   Node _newNode = new Node(data);
   if (_head == null)
   {
    _head = _newNode;
    _tail = _head;
   }
   else
   {
    _tail.Next = _newNode;
    _tail = _tail.Next;
   }
   _count++;
 }
 public int Dequeue()
 {
   if (_head == null)
   {
    throw new Exception("Queue is Empty");
   }
   int _result = _head.Data;
   _head = _head.Next;
   return _result;
 }
 public int Count
 {
   get
   {
    return this._count;
   }
 }
}