with sub1 as(
select
    row_number() over() ROW_NO,
    line_id,
    seat_no,
    rsv_status,
    lead(seat_no, 2) over() LEAD
from
    seat_reserve
where
    rsv_status = 0
order by
    line_id asc,
    seat_no asc
)

select
    line_id LINE,
    seat_no SEAT_F,
    LEAD SEAT_T
from
    sub1
where
    seat_no + 2 = LEAD
order by
    line_id desc,
    seat_no asc