Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE Lessons (staff_id VARCHAR); CREATE TABLE Staff (first_name VARCHAR); CREATE TABLE Staff (first_name VARCHAR, staff_id VARCHAR)
### Question:
What is the first name of the staff who did not give any lesson?
### Answer:
SELECT first_name FROM Staff EXCEPT SELECT T2.first_name FROM Lessons AS T1 JOIN Staff AS T2 ON T1.staff_id = T2.staff_id