?? ?????????????:??
????:1???????:????
2??????????
3?????v
4?????
5??????????
?1??20??????(???????????????? ??)????20???
?????????????????? ?????????? ?????????:???????????????????????,???????
?:???????,??,????????,??????????????
???????????????????????,???????????????,??,???????????????????????????,??????,????,???????????????(??????)
?????:?????????