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_15823956_1 ( episodes VARCHAR, region_1 VARCHAR )

### Question ###
Which episode was N/A in region 1

### Accurate SQL ###

SELECT episodes FROM table_15823956_1 WHERE region_1 = "N/A"