Help me bottom align these panels

Tops of A and C. Bottoms of B and C. Without flexbox, javascript, or breaking responsiveness!

by Mike Furlender

HTML

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/js/bootstrap.min.js"></script>
<div class="container-fluid">
  <div class="row toprow">
    <div class="col-xs-12 col-sm-3 col-sm-push-9">
      <div class="panel panel-default">
        <div class="panel-heading">Panel C</div>
        <div class="panel-body">
          <div class="row">
            <div class="col-xs-12"><img src="http://placehold.it/320x240" class="img-responsive img-thumbnail center-block img-rounded"></div>
            <div class="col-xs-12"><img src="http://placehold.it/320x240" class="img-responsive img-thumbnail center-block img-rounded"></div>
          </div>

        </div>
      </div>
    </div>
    <div class="col-xs-12 col-sm-9 col-sm-pull-3">
      <div class="panel panel-default">
        <div class="panel-heading">Panel A</div>
        <div class="panel-body">
          <div class="row">
            <div class="col-sm-4">
              <img class="img-responsive img-rounded center-block img-thumbnail" src="http://placehold.it/320x240">
            </div>

            <div class="col-sm-4">
              <img class="img-responsive img-rounded center-block img-thumbnail" src="http://placehold.it/320x240">
            </div>
            <div class="col-sm-4">
              <img class="img-responsive img-rounded center-block img-thumbnail" src="http://placehold.it/320x240">
            </div>
          </div>
        </div>
      </div>
      <div class="panel panel-default">
        <div class="panel-heading">Panel B</div>
        <div class="panel-body">
          <div class="row">
            <div class="col-xs-2"><img class="img-responsive img-rounded img-thumbnail center-block" src="http://placehold.it/320x240"></div>
            <div class="col-xs-2"><img class="img-responsive img-rounded img-thumbnail center-block" src="http://placehold.it/320x240"></div>
           ...

CSS

.toprow {
  background-color: lightblue;
}