Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_45 (first_elected VARCHAR, result VARCHAR, district VARCHAR)

### Question ###
Who was first elected as the result of a retired republican gain in the district of ohio 21?

### Accurate SQL ###

SELECT first_elected FROM table_name_45 WHERE result = "retired republican gain" AND district = "ohio 21"