The woodcutter's aim is to trim back this forest, so he will try to remove as much of the tree as possible each time he chops.

So, pieces that haven't been tampered with get priority when cutting. Confusing times.

No, not that leaf. An imaginary leaf, or a leaf from another twig. If you avoid negative numbers, you have basically modelled the thing such that leaves are not attached to specific twigs, and their sum total is calculated any time anything is cut. If there are no more leaves (imaginary or otherwise), then cutting a twig, branch or trunk will have no effect on their number (whcih remains 0), so in fact, you are not cutting the same leaf twice. The leaf isn't real.

If you cut a leave, then a twig, that leave is cut once more. This kata is messed up.

these dependencies make no sense at all

Aha - Thank you!

You have to return the result, not print it.

Python 3.4.3

Ruby, Crystal and c++.

True, it could be edited to ensure that someone writing in Python 2 won't get an error out of nowhere like with one of my other translations...

ah well, now I remember the right context, I believe...: it's better to declare it with the object so that you might avoid problems if by any chances someone uses the code with python 2. Well, not really a concern on CW, I guess.

x) Damn right! x)

But...

nope, it's the opposite