What is the sum of all points when number played is less than 18?
CREATE TABLE table_56157 (
    "Team" text,
    "Points" real,
    "Played" real,
    "Drawn" real,
    "Lost" real,
    "Against" real,
    "Diff" real
)
SELECT SUM("Points") FROM table_56157 WHERE "Played" < '18'
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 sum of all points when number played is less than 18? ### Input: CREATE TABLE table_56157 (
    "Team" text,
    "Points" real,
    "Played" real,
    "Drawn" real,
    "Lost" real,
    "Against" real,
    "Diff" real
) ### Response: SELECT SUM("Points") FROM table_56157 WHERE "Played" < '18'