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 services (service_name VARCHAR); CREATE TABLE party_services (service_id VARCHAR); CREATE TABLE services (service_name VARCHAR, service_id VARCHAR)
### Question:
Find name of the services that has never been used.
### Answer:
SELECT service_name FROM services EXCEPT SELECT t1.service_name FROM services AS t1 JOIN party_services AS t2 ON t1.service_id = t2.service_id