<!DOCTYPE html>
<html>
<head>
<title>Title of the document</title>
<style>
.container {
height: auto;
overflow: hidden;
}
.right {
width: 200px;
float: right;
background: #fffc54;
}
.left {
background: #e3e3dc;
width: auto;
overflow: hidden;
}
</style>
</head>
<body>
<div class="container">
<div class="right">Right part</div>
<div class="left">Left part</div>
</div>
</body>
</html>