Name the total number of production code for episode by steve cohen & andrew dettman
CREATE TABLE table_21550870_1 (
    production_code VARCHAR,
    written_by VARCHAR
)
SELECT COUNT(production_code) FROM table_21550870_1 WHERE written_by = "Steve Cohen & Andrew Dettman"
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: Name the total number of production code for episode by steve cohen & andrew dettman ### Input: CREATE TABLE table_21550870_1 (
    production_code VARCHAR,
    written_by VARCHAR
) ### Response: SELECT COUNT(production_code) FROM table_21550870_1 WHERE written_by = "Steve Cohen & Andrew Dettman"