Q&A for anime and manga fans
SELECT COUNT(DISTINCT u.Id) AS NumberOfUsers FROM Users u JOIN Badges b1 ON u.Id = b1.UserId AND b1.Name = 'Civic Duty' JOIN Badges b2 ON u.Id = b2.UserId AND b2.Name = 'Strunk & White' JOIN Badges b3 ON u.Id = b3.UserId AND b3.Name = 'Deputy' JOIN Badges b4 ON u.Id = b4.UserId AND b4.Name = 'Convention' WHERE u.Reputation >= 3000;