with tkoo as (
select 1 a from dual
union all
select 2 from dual
union all
select 3 from dual
union all
select 4 from dual
union all
select 5 from dual
union all
select 6 from dual
union all
select 8 from dual
union all
select 9 from dual
union all
select 10 from dual
)
with koo as (
select
rownum cd ,
a - rownum cd3,
a
from tkoo
)
select min(a), max(a) from koo
group by cd3
order by 1;