using System;
using System.Linq;
using System.Collections;
using System.Collections.Generic;
using System.Xml;
using System.Xml.Linq;
public class MainClass {
public static void Main() {
XElement xBookParticipant = new XElement("Book");
XComment xComment = new XComment("This person is retired.");
xBookParticipant.Add(xComment);
Console.WriteLine(xBookParticipant);
}
}