How to add ad code in category and tag page

Hi WordPress Experts

I want to place ad code without any plugins, so please tell me how to do it?

I placed ad code on index php but category and tag php have diffrent code, here is example:

Index.php:

<?php /* Start the Loop */ ?>
<?php while ( have_posts() ) : the_post(); ?>
<?php get_template_part( ‘content’, get_post_format() ); ?>
<?php endwhile; ?>

category and tag php:

<?php
/* Start the Loop */
while ( have_posts() ) : the_post();

/* Include the post format-specific template for the content. If you want to
* this in a child theme then include a file called called content-___.php
* (where ___ is the post format) and that will be used instead.
*/
get_template_part( ‘content’, get_post_format() );

endwhile;

I am using this code on index php:

<?php /* Start the Loop */ ?>
<?php $count = 1; ?>
<?php while ( have_posts() ) : the_post(); ?>
<?php get_template_part( ‘content’, get_post_format() ); ?>
<?php if ($count == 1) : ?>
//ad code……
<?php endif; $count++; ?>
<?php endwhile; ?>

Please tell me a working solution as soon as possible.

Thanks in Advance