Solve: Identify a Suspect

Created By: Miguel Fernandez

$/$Version: $2021\mathrm{.}8\mathrm{.}0$

There was a theft of research hardware on campus last night. Based on eyewitness accounts, they figured out the suspect went through the Siebel Center for Computer Science, the Digital Computing Laboratory, and the Illini Union. Luckily, you have the lists of the people who entered each building from their I$-$Card ID swipes.

You've been given three non$-$null Set