<?xml version="1.0" encoding="UTF-8"?>
<root>
    <x>
        <y1>
            <z>
                <a1>1111</a1>
                <a2>2222</a2>
            </z>
        </y1>
        <y2>
            <b2>3333</b2>
        </y2>
    </x>
</root>