Neowaring

<script>
    $(document).ready(function () {
        $('.thumbnail-container-images .img-fluid').click(function () {
            var imgThumb = $(this).attr('src');
            var oldImg = $(this).closest('.thumbnail-container-images').find('.full_img');
            oldImg.attr('src', imgThumb);
        });
    });
    $('thumb:first').click();
</script>