You don't have to do anything with your adsense code as some blods might tell you to parse your adsense code but no need to do that.
Just follow these simple steps:
Step 1: First of all you need to enable Show ads between every post.If you already have this option enabled in your blog then skip to Step 3. To enable it go to Layout and Edit Blog Posts
Step 2: A window will appear where you will find Show ads between posts as shown in the image below. Enable it by checking the option as shown and set the ads occurrence to show after every 5 posts. Next choose the ad size which you want to show below your post title and customize your color scheme and save it.
Step 3: Go to Layout >> Edit HTML and look for the code mentioned below
Select this entire code and cut it.
Step 4: Now look for the code mentioned below in your blogger template
Pate the code mentioned in Step 3 just above the line
Step 5: Save your template and check your blog for changes.