Name the engine with chassis of maserati 250f and entrant of luigi piotti with year less than 1957
CREATE TABLE table_69620 (
    "Year" real,
    "Entrant" text,
    "Chassis" text,
    "Engine" text,
    "Points" real
)
SELECT "Engine" FROM table_69620 WHERE "Chassis" = 'maserati 250f' AND "Entrant" = 'luigi piotti' AND "Year" < '1957'
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: Name the engine with chassis of maserati 250f and entrant of luigi piotti with year less than 1957 ### Input: CREATE TABLE table_69620 (
    "Year" real,
    "Entrant" text,
    "Chassis" text,
    "Engine" text,
    "Points" real
) ### Response: SELECT "Engine" FROM table_69620 WHERE "Chassis" = 'maserati 250f' AND "Entrant" = 'luigi piotti' AND "Year" < '1957'