<!DOCTYPE html>
<div style="float: left">
first
</div>
<div style="display: flow-root">
<div style="width: 100%">second</div> second second second second second second second second second second second second second second second
</div>
<div style="display: flow-root">
third
</div>
<div style="float: left">
fourth
</div>
<div style="display: flow-root">
fifth
</div>