Give me some tests

I have no tests, but it could be overflow or wrong compare function

I had WA5 when I performed sort for X/Y and X/Z only. Adding sorting for Y/Z as well led to TL9 at least. I think that flipping X/Y around origin to make Y>=0 and flipping X/Z around origin to make Z>=0 later cannot be done independently, or there is some other problem of this type.