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add_filter('the_content', 'kf__thumbnail_before_content');

function kf__thumbnail_before_content($content) {
    global $post;
    if (is_singular('post') && has_post_thumbnail()) {
        $featuredimage = get_the_post_thumbnail($post->ID, 'full');
        $content = '<div class="classname">' . $raiting . $featuredimage . '</div>' . $content;
    }

    return $content;
}