Good linux. Good free program. You know how to merge PDFs without paying $5,000 for Adobe Acrobat, don't you? Yes, you do! Yes you do! You're a good operating system. Good boy, linux. Good boy!
I only need a one time thing though. I'd never re-use this program again. There are other programs that I've found that are around $30, but like I said, it's only for a one-time use.