System Xml Xpath C# by API

using System;
using System.Collections.Generic;
using System.Data;
using System.Text;
using System.Xml;
using System.Xml.XPath;
public class MainClass {
    public static void Main() {
        XPathDocument doc = new XPathDocument("books.xml");
        XPathNavigator nav = ((IXPathNavigable)doc).CreateNavigator();
        XPathNodeIterator iter = nav.Select("/bookstore/book[@genre='novel']");
        while (iter.MoveNext()) {
            XPathNodeIterator newIter = iter.Current.SelectDescendants(XPathNodeType.Element, false);
            while (newIter.MoveNext())
                Console.WriteLine(newIter.Current.Name + ": " + newIter.Current.Value);
        }
    }
}