Adsense plugins

Hello,

I want to make this as clear as possible to trouble shoot my problem.

I want to insert google adsense after every three-four posts.

I don’t want it in between the content what the normal adsense plugins can do for me, but after a couple of posts. I got short posts, that’s why.

If there is an plugin that can do that for me, please help me out.

If someone knows the coding what I have to put in and where exactly in my template, it would be awesome aswell.

Thank you for the help WordPressers!