What's the series number of the episode with season number 2?
CREATE TABLE table_22900 (
    "Series No." real,
    "Season No." real,
    "Title" text,
    "Directed by" text,
    "Written by" text,
    "Original air date" text,
    "U.K. viewers (million)" text
)
SELECT MIN("Series No.") FROM table_22900 WHERE "Season No." = '2'
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: What's the series number of the episode with season number 2? ### Input: CREATE TABLE table_22900 (
    "Series No." real,
    "Season No." real,
    "Title" text,
    "Directed by" text,
    "Written by" text,
    "Original air date" text,
    "U.K. viewers (million)" text
) ### Response: SELECT MIN("Series No.") FROM table_22900 WHERE "Season No." = '2'