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() {
XDocument xDocument = new XDocument(new XDocumentType("Books",null,"Books.dtd", null),new XElement("Book"));
Console.WriteLine(xDocument);
}
}