How do online and manual ballots converge to pick one grand prize winner?

I am playing a contest where I have 3680 manual entries and 3790 online entries for a grand prize of one of two vehicles on two different draw dates. I enter a higher than usual amount because people throw away their prize entry tickets. So my question is this...the rules state that they will pick a grand prize winner from the online and ballot boxes....how do they do this when the manual ballots are different from the online ballots. Does someone sit there and enter them all online or does a giant computer spit out manual tickets with names on them from the valid email addresses. The manual tickets would take up a lot of space and be too heavy for someone to rotate in a drum as the contest is running in 5 provinces in Canada.