On which surface was the score w/o?
CREATE TABLE table_15135 (
    "Outcome" text,
    "Date" text,
    "Tournament" text,
    "Surface" text,
    "Partner" text,
    "Opponents" text,
    "Score" text
)
SELECT "Surface" FROM table_15135 WHERE "Score" = 'w/o'
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: On which surface was the score w/o? ### Input: CREATE TABLE table_15135 (
    "Outcome" text,
    "Date" text,
    "Tournament" text,
    "Surface" text,
    "Partner" text,
    "Opponents" text,
    "Score" text
) ### Response: SELECT "Surface" FROM table_15135 WHERE "Score" = 'w/o'