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 region (region_name VARCHAR, region_id VARCHAR); CREATE TABLE affected_region (region_name VARCHAR, region_id VARCHAR)
### Question:
Show the name for regions not affected.
### Answer:
SELECT region_name FROM region WHERE NOT region_id IN (SELECT region_id FROM affected_region)