List the distinct hometowns that are not associated with any gymnast.
SELECT DISTINCT Hometown FROM people EXCEPT SELECT DISTINCT T2.Hometown FROM gymnast AS T1 JOIN people AS T2 ON T1.Gymnast_ID  =  T2.People_ID
distinct hometowns not associated with any gymnast refers to SELECT DISTINCT Hometown FROM people EXCEPT SELECT DISTINCT T2.Hometown FROM gymnast JOIN people ON gymnast.Gymnast_ID = people.People_ID;