I'd say 6kyu is fine. I get it can be a lot more difficult if you're not familiar with recursion yet.

Fixed.

+1 @PomPolock, I wrote the lambda until I realized I had to list() the filter object. Then re-wrote as a list comprehension. Surprised that the testing structure doesn't let you check for the method used (see https://www.codewars.com/kata/59441520102eaa25260000bf).

Ah, so you're trying to say thah it would have been better to use filter with a lambda function other than a conditional like this ?

I appreciate the feedback and I will look into it. Thank you!

Thanks!

Hi,

The python and ruby versions are waiting for the publication of updated versions. They currently are "incorrect" (requirements do not match other languages: those two versions are harder).

Tho, reading your comment, it seems probable that your code generate a lot of cases, then filter out the incorrect ones. You should try to avoid that.

EDIT: about the formatting:

```
#your code here
```