SELECT
    A.LINE_ID AS LINE,
    A.SEAT_NO
FROM
    SEAT_RESERVE AS A
WHERE
    A.RSV_STATUS =  0
    AND
    EXISTS (
        SELECT * FROM SEAT_RESERVE AS B
        WHERE B.LINE_ID = A.LINE_ID AND B.SEAT_NO = A.SEAT_NO + 1 AND B.RSV_STATUS =  0
    )
    AND
    EXISTS (
        SELECT * FROM SEAT_RESERVE AS B2
        WHERE B2.LINE_ID = A.LINE_ID AND B2.SEAT_NO = A.SEAT_NO + 2 AND B2.RSV_STATUS =  0
    )
ORDER BY
    A.LINE_ID DESC,
    A.SEAT_NO