<!DOCTYPE html>
<style>
.clamp {
  display: -webkit-inline-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 3;
}
</style>
<body>
  <div class="clamp">
    1<br>
    2<br>
    <div>3</div>
    4<br>
    5
  </div>
</body>