Delete all Even nodes of a circular linked list in c#

Csharp program for Delete all Even nodes of a circular linked list. Here problem description and explanation.

// Include namespace system
using System;
// Csharp program for
// Delete all even key nodes from circular linked list

// Define class of linked list Node
public class LinkNode
{
	public int data;
	public LinkNode next;
	public LinkNode(int data, LinkNode first)
	{
		this.data = data;
		this.next = first;
	}
}
public class CircularLinkedList
{
	public LinkNode head;
	// Class constructor
	public CircularLinkedList()
	{
		this.head = null;
	}
	// Insert node at end of circular linked list
	public void insert(int value)
	{
		// Create a node
		var node = new LinkNode(value, this.head);
		if (this.head == null)
		{
			// First node of linked list
			this.head = node;
			node.next = this.head;
		}
		else
		{
			var temp = this.head;
			// Find last node
			while (temp.next != this.head)
			{
				// Visit to next node
				temp = temp.next;
			}
			// Add new node at the last 
			temp.next = node;
		}
	}
	// Display node element of circular linked list
	public void display()
	{
		if (this.head == null)
		{
			Console.WriteLine("Empty Linked List");
		}
		else
		{
			Console.Write("Linked List Element :");
			var temp = this.head;
			// iterate linked list
			while (temp != null)
			{
				// Display node
				Console.Write("  " + temp.data.ToString());
				// Visit to next node
				temp = temp.next;
				if (temp == this.head)
				{
					// Stop iteration
					return;
				}
			}
		}
	}
	public void deleteEven()
	{
		if (this.head == null)
		{
			// When empty linked list
			return;
		}
		// Define some auxiliary variables
		// Get second node when exist
		var temp = this.head.next;
		var auxiliary = this.head;
		LinkNode hold = null;
		// Detect and remove even nodes from second node to 
		// last node in given linked list
		// assume linked list is circular
		while (temp != this.head)
		{
			// Get current node
			hold = temp;
			// visit to next node
			temp = temp.next;
			if (hold.data % 2 == 0)
			{
				// When even data of current node
				auxiliary.next = temp;
			}
			else
			{
				// Get current node
				auxiliary = hold;
			}
		}
		if (this.head.data % 2 == 0)
		{
			temp = this.head;
			// When need to remove head node
			if (this.head.next == this.head)
			{
				// When only one node exists in this linked list
				// Set empty linked list
				this.head = null;
			}
			else
			{
				// Set new head
				this.head = this.head.next;
				// Auxiliary is last odd node which 
				// Is get by above loop
				auxiliary.next = this.head;
			}
		}
	}
	public static void Main(String[] args)
	{
		var cll = new CircularLinkedList();
		// Linked list
		// 12 → 21 → 30 → 41 → 53 → 60 → 79 → 88 → To head
		cll.insert(12);
		cll.insert(21);
		cll.insert(30);
		cll.insert(41);
		cll.insert(53);
		cll.insert(60);
		cll.insert(79);
		cll.insert(88);
		Console.WriteLine(" Before delete ");
		cll.display();
		cll.deleteEven();
		Console.WriteLine("\n After delete even nodes");
		cll.display();
	}
}

Output

 Before delete
Linked List Element :  12  21  30  41  53  60  79  88
 After delete even nodes
Linked List Element :  21  41  53  79