Please list the IDs of all the faculty employees who teaches a basic or medium undergraduate course.
faculty employees refers to hasPosition = 'Faculty_eme'; basic or medium undergraduate course refers to courseLevel = 'Level_300'
SELECT T2.p_id FROM course AS T1 INNER JOIN taughtBy AS T2 ON T1.course_id = T2.course_id INNER JOIN person AS T3 ON T3.p_id = T2.p_id WHERE T1.courseLevel = 'Level_300' AND T3.hasPosition = 'Faculty_eme'