<html>
<head>
<style>
  body {
    /* Standize line-height, because the default varies by platform */
    line-height: 50px;
  }
  div#a {
    width: 3em;
    -moz-column-count: 2;
    -moz-column-gap: 0px;
    background: lightgreen;
  }
  div#b {
    float: left;
    background: lightblue;
  }
  div#c {
    height: 100px;
    background: orange;
  }
</style>
</head>
<body>
  <div id="a">
    <div id="b"><br/><br/>b</div>
    <div id="c">c c c</div>
  </div>
</body>
</html>