I have the same problem(Python). The maximum test that I can get to is 445, and I don't have any failed tests, that's it. I spent hours to solve this kata and at this moment I have at least 2 different solutions, which are definitely not O(n^2), cause I don't use nested for loops or something like that. However, it has nearly 9000 completions, so maybe it's me and I don't undestand how to optimize my code, but at the same time, I've read many comments and still some people have the same issue.

Interesting and unique Kata, Thanks! However,in my opinion it's definitely not 6 kyu, cause it was a bit difficult to understand the logic of it.