SELECT
     LINE_ID AS LINE
    ,F_NO AS SEAT_F
    ,L_NO AS SEAT_T
FROM(
    SELECT
         SR.LINE_ID AS LINE_ID
        ,SR.SEAT_NO AS F_NO
        ,(
        SELECT
            R.SEAT_NO
        FROM
            SEAT_RESERVE R
        WHERE
            R.SEAT_NO = SR.SEAT_NO +2
        ) AS L_NO
    FROM
        SEAT_RESERVE SR
    WHERE
        RSV_STATUS = '0'
    AND EXISTS(
        SELECT
            1
        FROM
            SEAT_RESERVE S
        WHERE
            S.SEAT_NO = SR.SEAT_NO + 1 
        AND EXISTS(
            SELECT 
                1
            FROM
                SEAT_RESERVE R
            WHERE
                R.SEAT_NO = S.SEAT_NO + 1
        )
    )
)