Update IF Block

<ul class="employees__list">
              <?php $counter = 0; $class = 'even'; ?>
              <?php while(have_rows('employee')): the_row(); ?>
                <?php
                  if($counter % 2 == 0) {
                    if($class == 'odd') {
                      $class = 'even';
                    } else {
                      $class = 'odd';
                    }
                  }
                ?>

                <li class="employees__list__employee<?php echo ' ' . $class; ?>">
                  <?php $image = wp_get_attachment_image_src(get_sub_field('image'), 'bio-pic'); ?>
                  <div class="employees__list__employee--image">
                    <?php if($image): ?>
                      <img src="<?php echo $image[0]; ?>" alt="" class="img-responsive">
                    <?php else: ?>
                      <img src="http://via.placeholder.com/600x600" alt="" class="img-responsive">
                    <?php endif; ?>
                  </div>

                  <div class="employees__list__employee__content">
                    <div class="employees__list__employee__content--wrap">
                      <h4 class="employees__list__employee__content--name"><?php echo get_sub_field('name'); ?></h4>
                      <h5 class="employees__list__employee__content--title"><?php echo get_sub_field('title'); ?></h5>
                      <p class="employees__list__employee__content--quote"><?php echo get_sub_field('quote', false); ?></p>
                    </div>
                  </div>
                </li>
              <?php $counter++; endwhile; ?>
            </ul>