SELECT DISTINCT T1.lastname FROM list AS T1 JOIN teachers AS T2 ON T1.classroom  =  T2.classroom WHERE T1.grade  =  3 AND T2.firstname != "COVIN" AND T2.lastname != "JEROME"
Find the last names of the students in third grade that are not taught by COVIN JEROME.
[Schema (values) (types)]: | student_1 |  list : lastname (text) , firstname (text) , grade (text) , classroom (number) | teachers : lastname (text) , firstname (text) , classroom (text);