clear: left

HTML

<!-- Learn about this code on MDN: https://developer.mozilla.org/fr/docs/Web/CSS/clear -->

<div class="wrapper">
  <div class="left">1</div>
  <div class="left">2</div>
  <div class="left">3</div>
</div>

CSS

.wrapper{
  border:1px solid black;
  width: 30px;
}

.left {
  border: 1px solid red;
  display: inline;
}