WITH threezeros AS (
    SELECT
        *
        , LAG(SEAT_NO, 1) OVER(ORDER BY LINE_ID, SEAT_NO) AS SEAT_F
        , LEAD(SEAT_NO, 1) OVER(ORDER BY LINE_ID, SEAT_NO) AS SEAT_T
        , SUM(RSV_STATUS) OVER(PARTITION BY LINE_ID ORDER BY LINE_ID, SEAT_NO ROWS BETWEEN 1 PRECEDING AND 1 FOLLOWING) as FLAG
    FROM 
        SEAT_RESERVE)
SELECT
    LINE_ID LINE
    , SEAT_F
    , SEAT_T
FROM
    threezeros
WHERE FLAG = 3
ORDER BY 
    LINE_ID DESC, SEAT_F ASC
;