Python Challenge ahead [NEW] for riddle lovers

[Reinhold Birkenfeld]

Dan Christensen wrote:
> Roel Schroeven <rschroev_nospam_ml at fastmail.fm> writes:
> 
>> There's no level 12 yet though.
> 
> Now there's a 12 and a 13 (at least!).

Anyone solved 12? Hints?

thanks, Reinhold