How to limit the output of images for a single post?

Question

WordPress

Hello, here is the code:

$images1 =& get_children( array (
    'post_parent' => $post->ID,
    'post_type' => 'attachment',
    'order' => 'ASC',
    'post_mime_type' => 'image'
  ));
  if ( empty($images1) ) {
    // no attachments here
  } else { ?>
  <div class="portfolio__wrap">
    <div class="portfolio__photo">
      <div class="row">
        <div class="carousel photo__carousel col col-xs-12 col-sm-10 col-sm-of-1 col-md-12 col-md-of-0">
          <?php foreach ( $images1 as $attachment_id => $attachment ) { ?>
          <div class="item">
            <a href="<?php echo wp_get_attachment_image_url($attachment_id, "full");?>"  
               class="fancybox-photos link__scale video__link" data-fancybox-group="photos" data-fancybox-title="<?php the_title(); ?>">
              <span class="bg__icon arrow"><span class="icon__plus"></span></span>
              <?php echo wp_get_attachment_image( $attachment_id, "medium"); ?></a>
          </div>
          <?php } ?>
        </div>
      </div>
    </div>
  </div>

The essence of the code is such that when media files are loaded, you can link to a specific page and display them.
I uploaded 50 photos, but I need 13 of them for the first SLIDER, and 37 for the second.
Question: how can I separate the pictures attached to one page, but to a different slider (using this code)?
PS I'll forgive the petition, for raising the question, perhaps I'm not explaining correctly.

Answer 1

$images_first = array_splice( $images, 0, 13); 

// массив $images_first  будет содержать первые 13 элементов масcива $images
// в массиве $images теперь будут содержаться только элементы которые изначально были после 13-го