Who is the staff manager of the store with the most non-active customers?
most non-active customer refers to Max(Count(active = 0))
SELECT T.first_name, T.last_name FROM ( SELECT T3.first_name, T3.last_name, COUNT(T1.customer_id) AS num FROM customer AS T1 INNER JOIN store AS T2 ON T1.store_id = T2.store_id INNER JOIN staff AS T3 ON T2.store_id = T3.store_id WHERE T1.active = 0 GROUP BY T3.first_name, T3.last_name ) AS T ORDER BY T.num DESC LIMIT 1