Urban Landreman

I have a large (i.e., many hundreds of pages) .pdf document that is composed of many 1- or 2-page documents. I know by certain content on the page whether a particular page is Page 1 or Page 2. My goal is to automate a process so I take the original .pdf document and generate a new .pdf document that is made up on only 2-page documents. So, if one of the sub-documents is only 1 page long, I want to insert a blank page as its corresponding "page 2". I know how in Adobe Acrobat the steps needed to insert a blank page. That's easy. The challenge is to automate process so I don't have to manually go through all hundreds of pages and insert a blank page when it's needed. Any suggestions or examples which I could adapt? Thanks.