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 table_name_90 (county VARCHAR, ihsaa_class VARCHAR, location VARCHAR)
### Question:
What is the county with an AA IHSAA class in ferdinand?
### Answer:
SELECT county FROM table_name_90 WHERE ihsaa_class = "aa" AND location = "ferdinand"