How to find the deepest node?

Hi,

I have the following XML-file (see below) and I need to find the deepest
node of 'title'.
The resultfile should only contain the titles 'Text 02' and 'Text 03',
because they are in this case the deepest nodes. The next XML-file I receive
may contain more nested levels of items and whatever the level of nesting I
only need to find the deepest titles.
I know I have to do something with recurse, but I don't know how to start.
Who can help me on this one?

Kind regards,
Bert


<?xml version="1.0" encoding="UTF-8"?>
<document>
  <item>
    <item>
      <title>Text 01</title>
    </item>
    <item>
      <item>
        <title>Text 02</title>
      </item>
    </item>
  </item>
  <item>
    <item>
      <item>
        <title>Text 03</title>
      </item>
    </item>
  </item>
  <item>
    <item>
      <title>Text 04</title>
    </item>
  </item>
</document>

Resultfile should contain:

<?xml version="1.0" encoding="UTF-8"?>
<document>
  <item>
    <item>
      <item>
        <title>Text 02</title>
      </item>
    </item>
  </item>
  <item>
    <item>
      <item>
        <title>Text 03</title>
      </item>
    </item>
  </item>
</document>