How to count the number of nodes with a certain name using the PugiXML?

Question

I'm using the PugiXML library in a C++ project and I have the following structure in an XML file. How can I count the number of Plan nodes?

<Profiles>
    <Plan>
        <Name>Foo</Name>
    </Plan>
    <Plan>
        <Name>Bar</Name>
    </Plan>
</Profiles>