how many persons got the fourth position when the regional was shikoku?
CREATE TABLE table_21632864_1 (
    fourth_place VARCHAR,
    regional VARCHAR
)
SELECT COUNT(fourth_place) FROM table_21632864_1 WHERE regional = "Shikoku"
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 persons got the fourth position when the regional was shikoku? ### Input: CREATE TABLE table_21632864_1 (
    fourth_place VARCHAR,
    regional VARCHAR
) ### Response: SELECT COUNT(fourth_place) FROM table_21632864_1 WHERE regional = "Shikoku"