Demoted from professor to PhD. The centre was a lot of fun to solve. It was tricky at first, but then it became intuitive.
Since my previous solved level got demoted, this would've been my new 100th professor if I didn't also demote this one.
How can you get this one so low? I'm at 156. EDIT: Figured it out 14 years later. Really nice picture (I like the touch of each ring having its own kind of block) and fun optimization process.
(12 years ago) Yaaay, finally I found it. 20 tries. :)
I like it ! :D
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EDIT 2023, 9th April: And agaaaain I was having troubles with this Christmass tree. :)) Had TWO very different two offs and some other combinations. It took quite a while to get the tree decorated in the right way, with exactly 55 decoration pieces. ;) :)) GREAT puzzle!