Count XML Child Nodes

This is how do you quickly count the child nodes of an XML file. Say that you have an XML data as follows:

< ?xml version="1.0" encoding="UTF-8"?>

  
    
      < title>Sql Server 2008 Query Performance ...< /title>
      978-1-4302-1902-6
    
    
      < title>Pro ASP.NET MVC Framework< /title>
      978-1-4302-1007-8
    
  

To count the book items you may use counter iterating the books/book tags but this is how do you get the total number of book nodes in only one line.

Dim document As New XmlDocument
document.Load(xmlfilepath)
Dim count As Integer = document.SelectNodes("inventory/books/book").Count

Enjoy!