????:1????????????:????vx

2??????wx

3????????

4???????

5???????????

???1?4????????????????? (????? ????????????????)????????????????????????4???,??,?3????,??

????????????,???4???????10?????????????30????,???????22???????????,???3???????????????19??????????,??,????????

???,????????????????????????????,??????????????????????????????????????????????,???

??????????????,?????????????????????????????,???(?) ?????????:???