Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE prereq ( course_id VARCHAR )
TABLE: CREATE TABLE course ( course_id VARCHAR )

### Question ###
Find the id of the courses that do not have any prerequisite?

### Accurate SQL ###

SELECT course_id FROM course EXCEPT SELECT course_id FROM prereq