How many metropolitan boroughs have dorridge as a station?
CREATE TABLE table_15366849_1 (
    c_ VARCHAR,
    metropolitan_borough_ VARCHAR,
    station VARCHAR
)
SELECT COUNT(metropolitan_borough_) AS "c_" FROM table_15366849_1 WHERE station = "Dorridge"
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: How many metropolitan boroughs have dorridge as a station? ### Input: CREATE TABLE table_15366849_1 (
    c_ VARCHAR,
    metropolitan_borough_ VARCHAR,
    station VARCHAR
) ### Response: SELECT COUNT(metropolitan_borough_) AS "c_" FROM table_15366849_1 WHERE station = "Dorridge"