Hide hamburger menu on click outside the menu

Question

I have hamburger menu which works great, but I want to add some funtion, which will hide menu when user clicks OUTSIDE the whole hamburger menu.

$(".cross").hide();
$(".mobilemenu").hide();
$(".hamburger").click(function() {
  $(".mobilemenu").slideToggle("slow", function() {
    $(".hamburger").hide();
    $(".cross").show();
  });
});

$(".cross").click(function() {
  $(".mobilemenu").slideToggle("slow", function() {
    $(".cross").hide();
    $(".hamburger").show();
  });
});

$(".clickham").click(function() {
  $(".mobilemenu").slideToggle("slow", function() {
    $(".cross").hide();
    $(".hamburger").show();
  });
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<header>
  <button class="hamburger">&#9776;</button>
  <button class="cross">&#735;</button>
</header>
<div class="mobilemenu">
  <ul>
    <a href="#" class="clickham">
      <li>Test</li>
    </a>
    <a href="#" class="clickham">
      <li>Test2</li>
    </a>
  </ul>
</div>

http://jsfiddle.net/71hdnctp/