Translate the following question to SQL: For each classroom report the grade that is taught in it. Report just the classroom number and the grade number.

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 classroom ,  grade FROM list
assistant