Exploiting the human factor

[Pilsener]

I made a hcmask-file looking like this:

?l?l?l?l?l?l?l?l
?l?l?l?l?l?l?l?l?l
?l?l?l?l?l?l?l?l?l?l

?u?l?l?l?l?l?l?l
?u?l?l?l?l?l?l?l?l
?u?l?l?l?l?l?l?l?l?l

?l?l?l?l?l?l?l?d
?l?l?l?l?l?l?d?d
?l?l?l?l?l?d?d?d

?l?l?l?l?l?l?l?l?d
?l?l?l?l?l?l?l?d?d
?l?l?l?l?l?l?d?d?d

?l?l?l?l?l?l?l?l?l?d
?l?l?l?l?l?l?l?l?d?d
?l?l?l?l?l?l?l?d?d?d

?u?l?l?l?l?l?l?d
?u?l?l?l?l?l?d?d
?u?l?l?l?l?d?d?d

?u?l?l?l?l?l?l?l?d
?u?l?l?l?l?l?l?d?d
?u?l?l?l?l?l?d?d?d

?u?l?l?l?l?l?l?l?l?d
?u?l?l?l?l?l?l?l?d?d
?u?l?l?l?l?l?l?d?d?d



I think it covers all the combinations I wanted.
Worth a try. It says it will take 11 days to complete, which is acceptable.

But I'm still interested in suggestions for modifications.