It is hard to answer without spoiling. Yes you have to know everyone. This COULD be seen as a crypto challenge in a way and there are sites that have these exact images.
Anyone think I gave too much away please let me know.
Ah, I've gotten a break through, thanks. I thought you just had to know the name of the last name of the 80th man but it seems you would need to be more of a Prodigy in order to know the rest.