WITH tmp AS (
SELECT
    LINE_ID AS LINE
    ,SEAT_NO AS SEAT_F
    ,SEAT_NO + 2 AS SEAT_T
    ,RSV_STATUS
    ,LEAD(RSV_STATUS,1)  OVER (PARTITION BY LINE_ID ORDER BY SEAT_NO) AS t1
    ,LEAD(RSV_STATUS,2)  OVER (PARTITION BY LINE_ID ORDER BY SEAT_NO) AS t2
FROM
    SEAT_RESERVE
)
SELECT
    LINE
    ,SEAT_F
    ,SEAT_T
FROM
    tmp
WHERE
    t1 IS NOT NULL
    AND
    t2 IS NOT NULL
    AND
    (
    t1 + t2 + RSV_STATUS
    ) = 0
ORDER BY
    LINE DESC , SEAT_F ASC