with base as(
select
    *
from
    SEAT_RESERVE a
where
    a.RSV_STATUS = 0
)
, base2 as(
select
    a.LINE_ID
    ,a.SEAT_NO as SEAT_F
    ,b.SEAT_NO
from 
    base a
inner join
    base b
on
    a.LINE_ID = b.LINE_ID and a.SEAT_NO + 1 = b.SEAT_NO
)
select 
    a.LINE_ID as LINE
    ,a.SEAT_F
    ,b.SEAT_NO as SEAT_T
from
    base2 a
inner join
    base b
on
    a.LINE_ID = b.LINE_ID and a.SEAT_F+ 2= b.SEAT_NO
order by
    1 desc, 2 asc
;