计算XML中的特定XML节点

See this XML:

看到这个XML：

<CMP>
    <OMP3>
        <personmenu>
            <submenuid>502</submenuid>
            <submenuid>503</submenuid>
        </personmenu>
        <accountsmenu>
            <submenuid>517</submenuid>
            <submenuid>518</submenuid>
            <submenuid>519</submenuid>
        </accountsmenu>

        <reportsmenu>
            <submenuid>522</submenuid>
            <submenuid>528</submenuid>
            <submenuid>536</submenuid>
        </reportsmenu>
    </OMP3>

    <AMP3>
        <admissionmenu>
            <submenuid>702</submenuid>
            <submenuid>703</submenuid>
        </admissionmenu>
    </AMP3>
</CMP>
<CMP>
    <OMP3>