[Python]
I'm also getting the timeout issue, so I'm trying to optimize my solution.

However I personally think this might have some more sense if you separate the really big test for another kata, one specifically about optimization.
I know my code works. Not so fast for enormous numbers? Sure, but the kata is about Fundamentals.

Not exactly a run-on but this paragraph reads too complex.

Could you tell me how much money f he could, possibly, have (if m-n is big enough, you might have a lot of possible f...), the cost c of a "xxx" car and the cost b of a "yyy" boat in each possible case? So, I will have a better idea about his fortune.

The sentence in () is completely extra, the sentence before the parenthesis and the one after don't connect in any way, it's extremely confusing per se and the parenthesis doesn't help a bit. Get rid of the xxx and yyy descriptors, they add nothing of value to the problem. Not one comma is necessary in this paragraph.

I know this is mostly whining but there are three steps when reading a problem: seeing if I understand what's written, understanding the actual problem and then know how to solve it. It took me way more to understand what was written than the actual problem.

Lot of issues with the testing. There's no much congruency between the pre-submit tests and the post submit tests (have to edit the code mid-tests). I don't what that is, but it happened to me.