using System;
using System.IO;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
using System.Xml;
using System.Xml.XPath;
using System.Xml.Schema;
using System.Xml.Linq;
public class MainClass {
public static void Main() {
XDocument xDocument = new XDocument(
new XElement("Books",
new XElement("Book",
new XAttribute("type", "Author"),
new XElement("FirstName", "A"),
new XElement("LastName", "B")),
new XElement("Book",
new XAttribute("type", "Author"),
new XElement("FirstName", "C"),
new XElement("LastName", "D"))));
XElement bookParticipant = xDocument.XPathSelectElement("//Books/Book[FirstName='A']");
Console.WriteLine(bookParticipant);
}
}