?? ???????????????????????
????:1???sn??:???????
2?51???????
3?????
4?????
5?????????
?????????9??????????27??????????????? (?? ??????????????????????)???27?,???,???????10?1???(????????)
???????????:????????????9??????????27??????????????? (?? ??????????????????????)???27?,???,???????10?1???(????????)
???????????:???????:1???sn??:???????
2?51???????
3?????
4?????
5?????????
?????????9??????????27??????????????? (?? ??????????????????????)???27?,???,???????10?1???(????????)
???????????:???