?? ?????21?????????6??
????:1???????????:???????
2???????
3??????
4?????v
5??????????
?????????6?11??? (??????????? ?????????????????)???????????,6???????????????8?????????????,?????11??,????41??????????????42?,?????????????????????????????21??????6??????????????????
??????????????,?????????,??????,????????????????????????????????????6??????9??????,11???????17???????,?,??
???,?????,????????????????,??,??,????????????,???,???????????????,???????????
?????,?????,???,?,???????,?????????,?????????????,?????????(??) ??:??