นักเรียนที่อาศัยอยู่ในหอพักชายมีทั้งหมดกี่คน?ไม่จำเป็นต้องใช้โต๊ะทั้งหมด
What are the total number of students who are living in a male dorm?It is not neccessary to use all the tables.
 dorm_amenity:  amenid [ number]  amenity_name [ text] 
SELECT COUNT(*) FROM student AS T1 JOIN lives_in AS T2 ON T1.stuid = T2.stuid JOIN dorm AS T3 ON T3.dormid = T2.dormid WHERE T3.gender = 'M'