Question: What is the largest city in the country that contains the village of Olszewko?
Sentence (from "Olszewko, Masovian Voivodeship"): Olszewko is a village in the administrative district of Gmina Kuczbork-Osada, within Żuromin County, Masovian Voivodeship, in east-central Poland.
Relevant evidence: Yes