Shovan Sargunam on "Display Specific category and number of post"

Hi,

Currently I have blogs page which pulls content from these category - blog, news and video.

<?php $recent = new WP_Query(); ?>
<?php $recent->query('cat=4,cat=15,cat=159'); ?>

<?php while($recent->have_posts()) : $recent->the_post(); ?>
	<div class="row <?php if ( $post->ID == $wp_query->post->ID ) { echo ' first-post yellow-higlight'; } else {} ?> blog-post">

I would like to limit number of post shown on that page to 5.

I believe the code I have written need to be modified or updated.

Any suggestion would help