XML C#

using System;
using System.Linq;
using System.Xml;
using System.Xml.Linq;
using System.Collections;
using System.Collections.Generic;
using System.Xml.XPath;
public class MainClass{
   public static void Main(){
            
        XPathDocument document = new XPathDocument("books.xml");
        XPathNavigator navigator = document.CreateNavigator();
        
        XPathNodeIterator nodes = navigator.SelectDescendants("book", "", false);
        
        XPathExpression expr = navigator.Compile("book[@genre='data']");
        while (nodes.MoveNext())
        {
            XPathNavigator navigator2 = nodes.Current.Clone();
            if (navigator2.Matches(expr))
            {
                navigator2.MoveToFirstChild();
                Console.WriteLine("Book title:  {0}", navigator2.Value);
            }
        }
    }
}