select
    LINE,
    SEAT_F,
    SEAT_T
from
(
    select
        LINE_ID LINE,
        LAG(SEAT_NO, 2) over(partition by LINE_ID) SEAT_F,
        SEAT_NO SEAT_T,
        A - LAG(A, 3) over(partition by LINE_ID) A
    from
    (
        select
            LINE_ID,
            SEAT_NO,
            sum(cast(RSV_STATUS as int)) over(partition by LINE_ID order by SEAT_NO) A
        from
            SEAT_RESERVE
    )
)
where
    SEAT_F is not null
    and A = 0
order by
    LINE desc,
    SEAT_F