Translate the following question to SQL: Find the last names of the students in third grade that are not taught by COVIN JEROME.

Schema: CREATE TABLE list (
    LastName TEXT   PRIMARY KEY,
    FirstName TEXT   PRIMARY KEY,
    Grade INTEGER,
    Classroom INTEGER,
    PRIMARY KEY (LastName, FirstName),
    UNIQUE (LastName, FirstName)
);

CREATE TABLE teachers (
    LastName TEXT   PRIMARY KEY,
    FirstName TEXT   PRIMARY KEY,
    Classroom INTEGER,
    PRIMARY KEY (LastName, FirstName),
    UNIQUE (LastName, FirstName)
);
user
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"
assistant