????:1????????:???????

2??????

3???????

4?????????????

5?????????

????2???????15????????????????? (?????? ????)??????????????15?,2?,??,?????????????

???????????????????????????,????????????,????????????????????????????????????????,????????2??(2???????????16???????28??????????????)???????

???????????????,2???????????????????,??????????????????????????????????????????????,?????,???????????,????????????????????????????????????????????,?????????????????????

2????,??,?????????,??,?,????????????,???

?,2?????????????,?????????,????????,??,??,????????????????????,??????????,???????,???????????2???????,??,??????(???????????) ?????:???????????