How many different pairs of writers wrote the episode with series number 56?
CREATE TABLE table_29584601_1 (written_by VARCHAR, no_in_series VARCHAR)
SELECT COUNT(written_by) FROM table_29584601_1 WHERE no_in_series = 56
<s>[INST] Write mssql query to answer the following question given the database schema. Schema: CREATE TABLE table_29584601_1 (written_by VARCHAR, no_in_series VARCHAR) Question: How many different pairs of writers wrote the episode with series number 56? [/INST] SELECT COUNT(written_by) FROM table_29584601_1 WHERE no_in_series = 56 </s>