<?php if ( have_posts() ) while ( have_posts() ) : the_post(); ?>

				<?php if ( has_post_thumbnail() ) : ?>
				// check if the post has a Post Thumbnail assigned to it.
  					<a href="<?php the_content(); ?>"><?php the_post_thumbnail( 'hero-post-thumbnail' ); ?></a>

				<?php else: the_content(); ?>

				<?php endif ?>
			<?php endwhile; // end of the loop. ?>