How many neighborhoods can be found in the Forest Glen community area?
"Forest Glen" is the community_area_name; neighborhoods refers to neighborhood_name
SELECT SUM(CASE WHEN T2.community_area_name = 'Forest Glen' THEN 1 ELSE 0 END) FROM Neighborhood AS T1 INNER JOIN Community_Area AS T2 ON T1.community_area_no = T2.community_area_no