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<div> <span></span><span><span>X</span></span></div>
<div><span></span> <span></span><span><span>X</span></span></div>
<div><span></span><span></span> <span><span>X</span></span></div>
<div><span></span><span></span><span> <span>X</span></span></div>
<div><span></span><span></span><span><span> X</span></span></div>
<div><span></span><span></span><span><span style="margin: 20px"> X</span></span></div>
<div><span></span><span></span><span><span style="padding: 20px"> X</span></span></div>