Who is the writer of episode 13?
CREATE TABLE table_2226817_8 (written_by VARCHAR, no_in_season VARCHAR)
SELECT COUNT(written_by) FROM table_2226817_8 WHERE no_in_season = 13
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_2226817_8 (written_by VARCHAR, no_in_season VARCHAR) Question: Who is the writer of episode 13? [/INST] SELECT COUNT(written_by) FROM table_2226817_8 WHERE no_in_season = 13 </s>