How many episodes were written by Warren Leight?
CREATE TABLE table_30977 (
    "Season no." real,
    "Series no." real,
    "Title" text,
    "Directed by" text,
    "Written by" text,
    "Original air date" text,
    "Production code" real,
    "U.S. viewers (millions)" text
)
SELECT COUNT("Season no.") FROM table_30977 WHERE "Written by" = 'Warren Leight'
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 episodes were written by Warren Leight? ### Input: CREATE TABLE table_30977 (
    "Season no." real,
    "Series no." real,
    "Title" text,
    "Directed by" text,
    "Written by" text,
    "Original air date" text,
    "Production code" real,
    "U.S. viewers (millions)" text
) ### Response: SELECT COUNT("Season no.") FROM table_30977 WHERE "Written by" = 'Warren Leight'