How many category id have low review count and rating more than 2?
rating more than 2 refers to stars > 2;
SELECT COUNT(DISTINCT T1.category_id) FROM Categories AS T1 INNER JOIN Business_Categories AS T2 ON T1.category_id = T2.category_id INNER JOIN Business AS T3 ON T2.business_id = T3.business_id WHERE T3.review_count = 'Low' AND T3.stars > 2