if else statement for taxonomy

I have what I think is a simple request, but beyond my knowledge at the moment.

I have to use the one template for my single post type but I need an if statement so that if the taxonomy i A, do this, else if its B do this

Currently I have the following which works for just one taxonomy.. how do I change this so it works for both category-a & category-b (if category-a {do this} else category b {do this})

<?php
global $post;
$terms = get_the_terms($post->ID, 'category-a');
$slugs = array();
foreach ( $terms as $term )
$slugs[] = $term->slug;
$other_posts = new WP_Query('post_type=accommodation&category-a='.$slugs[0].'&showposts=30&orderby=menu_order');
if ($other_posts->have_posts()):
while ($other_posts->have_posts()): $other_posts->the_post();
echo "
do stuff ";
endwhile;
endif;
wp_reset_query(); ?>

any help is appreciated