List any five of course IDs with professor IDs who taught master courses.
professor IDs refers to taughtBy.p_id; master course refers to courseLevel = 'Level_500'
SELECT T1.course_id, T2.p_id FROM course AS T1 INNER JOIN taughtBy AS T2 ON T1.course_id = T2.course_id WHERE T1.courseLevel = 'Level_500' LIMIT 5