the codes listed here is part of the following article : https://www.mwordpress.net/how-to-put-adsense-into-post-in-wordpress/

adsense-responsive.html

<script async src="//pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script>
<ins class="adsbygoogle"
	style="display:block"
	data-ad-client="ca-pub-XXXXXXXXXXXXXXX"
	data-ad-slot="XXXXXXXXXX"
	data-ad-format="auto">
</ins>
<script> (adsbygoogle = window.adsbygoogle || []).push({}); </script>

style.css

.ads-s300x250{
   outline:none;
   float:right;
   margin:0px 5px 0px 5px;
   padding:3px;
}