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_25721_3 ( episode_no INTEGER, airdate VARCHAR )

### Question ###
Which episode number aired on 18 october 2012?

### Accurate SQL ###

SELECT MIN(episode_no) FROM table_25721_3 WHERE airdate = "18 October 2012"