foreach loop with different classes for even / odd posts - php

Question

I'm trying to display odd and even posts, with different classes and sub-classes in a foreach loop in Laravel. I can't find anything in the documentation that suggests how to pull odd data differently from even data in a foreach loop.
#foreach ($posts as $post)
<li class="timeline-inverted">
<div class="timeline-badge primary" ><a title="{{ $post->created_at }}"><i class="glyphicon glyphicon-time invert" id=""></i></a></div>
<div class="timeline-panel">
<div class="timeline-header">
<div class="row">
<div class="col-xs-2">
<img class="img-responsive img-rounded" src="https://s.gravatar.com/avatar/2efde286ce7b0171a0dfedd1f3cff984?s=80&d=&r=G"">
</div>
<div class="col-xs-8">
<a> {{ $post->title }} </a> shared 6 hours ago
</div>
</div>
</div>
<div class="timeline-heading">
<div class="videowrapper">
<iframe height="300" src="https://www.youtube.com/embed/4PXXQzME5no" frameborder="0" allowfullscreen=""></iframe>
</div>
</div>
<div class="timeline-body">
<p>{{ $post->body }}</p>
</div>
<div class="timeline-footer">
<div class="media">
<a class="pull-left" href="#">
<img class="media-object" src="" />
</a>
<div class="media-body">
<p>Comment</p>
November at 8:15am
</div>
</div>
<hr>
<div class="media">
<a class="pull-left" href="#">
<img class="media-object" src="" />
</a>
<div class="media-body">Comment </div>
</div>
<hr>
<div class="media">
<a class="pull-left" href="#">
<img class="media-object" src="" />
</a>
<div class="media-body">Comment </div>
</div>
</div>
</div>
</li>
<li>
<div class="timeline-badge primary" ><a title="11 hours ago via Twitter"><i class="glyphicon glyphicon-time invert" id=""></i></a></div>
<div class="timeline-panel">
<div class="timeline-header">
<div class="row">
<div class="col-xs-2">
<img class="img-responsive img-rounded" src="https://s.gravatar.com/avatar/2efde286ce7b0171a0dfedd1f3cff984?s=80&d=&r=G"">
</div>
<div class="col-xs-8">
<a> {{ $post->title }} </a> shared 6 hours ago
</div>
</div>
</div>
<div class="timeline-heading">
<img class="img-responsive" src="img/img.png" />
<div class="timeline-images">
<div class="row">
<div class="col-xs-4">
<img src="img/img1.png" class="img-thumbnail img-responsive" />
</div>
<div class="col-xs-4">
<img src="img/img2.png" class="img-thumbnail img-responsive" />
</div>
<div class="col-xs-4">
<img src="img/img3.png" class="img-thumbnail img-responsive" />
</div>
</div>
</div>
</div>
<div class="timeline-body">
<p>{{ $post->body }}</p>
</div>
</div>
</li>
#endforeach