how many teams did they not lose to ?
CREATE TABLE table_203_506 (
    id number,
    "opponent" text,
    "played" number,
    "won" number,
    "lost" number,
    "drawn" number,
    "% won overall" text
)
SELECT COUNT("opponent") FROM table_203_506 WHERE "lost" = 0
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 teams did they not lose to ? ### Input: CREATE TABLE table_203_506 (
    id number,
    "opponent" text,
    "played" number,
    "won" number,
    "lost" number,
    "drawn" number,
    "% won overall" text
) ### Response: SELECT COUNT("opponent") FROM table_203_506 WHERE "lost" = 0