Which school has the smallest amount of professors?
SELECT T1.school_code FROM department AS T1 JOIN professor AS T2 ON T1.dept_code  =  T2.dept_code GROUP BY T1.school_code ORDER BY count(*) LIMIT 1
SELECT T1.school_code FROM department AS T1 JOIN professor AS T2 ON T1.dept_code  =  T2.dept_code GROUP BY T1.school_code ORDER BY count(*) LIMIT 1
[{'SCHOOL_CODE': 'BUS'}]