with tmp as (
    select
        line_id, seat_no, rsv_status,
        lead(rsv_status, 1) over (partition by line_id order by seat_no) n_rsv_status,
        lead(rsv_status, 2) over (partition by line_id order by seat_no) nn_rsv_status
    from seat_reserve
)
select
    line_id LINE,
    seat_no SEAT_F,
    seat_no + 2 SEAT_T
from tmp
where rsv_status = '0' and n_rsv_status = '0' and nn_rsv_status = '0'
order by LINE desc, SEAT_F asc