what is the surface for the week of october 25?
CREATE TABLE table_9218 (
    "Tournament" text,
    "Surface" text,
    "Week" text,
    "Winner and score" text,
    "Finalist" text,
    "Semifinalists" text
)
SELECT "Surface" FROM table_9218 WHERE "Week" = 'october 25'
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 is the surface for the week of october 25? ### Input: CREATE TABLE table_9218 (
    "Tournament" text,
    "Surface" text,
    "Week" text,
    "Winner and score" text,
    "Finalist" text,
    "Semifinalists" text
) ### Response: SELECT "Surface" FROM table_9218 WHERE "Week" = 'october 25'