Passage: The tournament proper begins with a group stage of 32 teams, divided into eight groups. Seeding is used whilst making the draw for this stage, whilst teams from the same nation may not be drawn into groups together. Each team meets the others in its group home and away in a round-robin format. The winning team and the runners-up from each group then progress to the next round. The third-placed team enters the UEFA Europa League.

Question: How many teams are involved in the tournament?
32