But is it a simple loop? I've done it a thousand times and it's always been fine. And then suddenly it started like this

what is the faster solution? coz mine is basically yours but it took 7k seconds to run lol.

Thanks for wise advice

The square brackets aren't needed. And using them creates a list that makes your solution O(n) in space when can be solved in O(1) space.

Ha, it was the only solution since apparently I don't know Python well enough to get by for a simple 6kyu :)