<!DOCTYPE html>
<html>
<body>
    <div style="overflow: hidden; width: 30px; height: auto;">
        <div style="margin-bottom: 20px; width: 20px; height: 50px;">
            <div style="margin-bottom: 40px; width: 20px; height: 50px;"></div>
        </div>
    </div>
    <div style="overflow: hidden; width: 50px; height: auto;">
        <div style="margin-bottom: 50px; width: 40px; height: 50px;"></div>
        <div style="margin-top: 60px; width: 40px; height: 50px;"></div>
    </div>
    <div style="margin-top: 50px; width: 40px; height: 50px;"></div>
</body>
</html>