Fixed.

Thanks for bringing this up. Added the following detail to the Description:

• A "worker" is a foreigner entrant who has WORK listed as their purpose on their access permit

Also made an update to specify which documents pertain to what types of entrants (ie. native, foreigner, or both).

Rolling back len-n+1 should be correct. I'm guessing that there are some subtleties in your solution that are missing in order to solve the more complex random problems (Some strange combination of resets/passes/rollbacks/moves is breaking your code and is not tested for explicitly in basic tests). It's hard to say what could be throwing your code off. It would be very strange if you could pass all the random tests and not any of the basic ones.

Are you sure you're not mutating the input? I tried with print(puzzle) several times and all input values seem ok.