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 customer (first_name VARCHAR, customer_id VARCHAR, rental_date INTEGER); CREATE TABLE rental (first_name VARCHAR, customer_id VARCHAR, rental_date INTEGER)
### Question:
What are the first names of customers who have not rented any films after '2005-08-23 02:06:01'?
### Answer:
SELECT first_name FROM customer WHERE NOT customer_id IN (SELECT customer_id FROM rental WHERE rental_date > '2005-08-23 02:06:01')