Display the number of 9-star votes the episode Sideshow received.
9-star vote refers to stars = '9'; episode Sideshow refers to title = 'Sideshow'
SELECT T2.votes FROM Episode AS T1 INNER JOIN Vote AS T2 ON T1.episode_id = T2.episode_id WHERE T2.stars = 9 AND T1.title = 'Sideshow'