According to the source (http://citypopulation.de/en/poland/cities/) Katowice does not have a population above 500,000 as of the 2019 estimate. Yet Krakow, Lodz, Wroclaw, Poznan (and Warsaw) all do.
I checked and it is spelled as "Zaporizhia" in my source. Upon further inspection, it seems both it and "Zaporizhzhia" are valid spellings for the cities. So I have edited the type ins to also allow the latter one as an acceptable answer.
Only Baltic countries are North Europe
Thanks for pointing it out!