Question: In which season and league did the Hellas Verona Football club compete against 21 other teams?
Sentence (from "2017–18 Hellas Verona F.C. season"): The 2017–18 season is Hellas Verona Football Club's first season back in Serie A following the club's relegation to Serie B at the end of the 2015–16 season.
Relevant evidence: No