I have large documents (150+ pages) that randomly contain both letter and legal size pages. When printing out such a document Adobe will "choose page source by pdf page size." After signing, marking, etc. the documents, I need to scan them back into my computer to return them to the sender. When I try to do this Adobe scans all of the pages, both letter and legal size, to legal size. How can I correct this and have Adobe create a pdf with the correct page sizes based on what I scanned in?