?? ??????:????????????? ???????
????:1??????????:????v
2??????????
3??????????
4???????150
5???????????
???6????????16???????????????????6???????????????,??????????????????,?????????,?????6?19?,??,??
6????????20?,???,?????,??????,??,??,????????,????????????????????,?????????
(? ???????? ?????????? ????? ???????)
???:??????????