Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE rooms (roomid VARCHAR, room VARCHAR); CREATE TABLE reservations (roomid VARCHAR, room VARCHAR)
### Question:
Find the number of rooms that do not have any reservation.
### Answer:
SELECT COUNT(*) FROM rooms WHERE NOT roomid IN (SELECT DISTINCT room FROM reservations)