Exclude tags from Related Posts

Hi guys!

I want to exclude 3 tags from my related posts. For related posts, I don’t use a plugin, I use this code:

`<!– Related Posts –>
<?php $orig_post = $post;
global $post;
$tags = wp_get_post_tags($post->ID);

if ($tags):
$tag_ids = array();
foreach($tags as $individual_tag) $tag_ids[] = $individual_tag->term_id;
$number_of_posts = 4; // number of posts to display
$query = “
SELECT “.$wpdb->posts.”.*, COUNT(“.$wpdb->posts.”.ID) as q
FROM “.$wpdb->posts.” INNER JOIN “.$wpdb->term_relationships.”
ON (“.$wpdb->posts.”.ID = “.$wpdb->term_relationships.”.object_id)
WHERE “.$wpdb->posts.”.ID NOT IN (“.$post->ID.”)
AND “.$wpdb->term_relationships.”.term_taxonomy_id IN (“.implode(“,”,$tag_ids).”)
AND “.$wpdb->posts.”.post_type = ‘post’
AND “.$wpdb->posts.”.post_status = ‘publish’
GROUP BY “.$wpdb->posts.”.ID
ORDER BY q
DESC LIMIT “.$number_of_posts.””;
$related_posts = $wpdb->get_results($query, OBJECT);
if($related_posts): ?>
<div class=”related-posts”>
<h3>Related posts</h3>
<?php foreach($related_posts as $post): ?>
<?php setup_postdata($post); ?>
<div class=”related-thumb”>
<a href=”<?php the_permalink()?>”>
<?php the_post_thumbnail(‘medium’); ?><br/>
<?php the_title(); ?>
</a>
</div>
<?php endforeach; ?>
</div>
<?php endif;
endif;
$post = $orig_post;
wp_reset_query(); ?>`

How can I do that?

Thank you!