WITH SEAT_STATUS AS (
    SELECT
        LINE_ID,
        SEAT_NO,
        RSV_STATUS,
        LEAD(RSV_STATUS, 1) OVER (PARTITION BY LINE_ID ORDER BY SEAT_NO) AS NEXT1,
        LEAD(RSV_STATUS, 2) OVER (PARTITION BY LINE_ID ORDER BY SEAT_NO) AS NEXT2
    FROM
        SEAT_RESERVE
),
AVAILABLE_SEATS AS (
    SELECT
        LINE_ID,
        SEAT_NO AS SEAT_F,
        SEAT_NO + 2 AS SEAT_T
    FROM
        SEAT_STATUS
    WHERE
        RSV_STATUS = '0'
        AND NEXT1 = '0'
        AND NEXT2 = '0'
)
SELECT
    LINE_ID AS LINE,
    SEAT_F,
    SEAT_T
FROM
    AVAILABLE_SEATS
ORDER BY
    LINE DESC,
    SEAT_F ASC;