???　?????　
?‥1?????　???????÷?????????????????÷?×????????±?2??????????????×????　???÷?????　???????÷?????????????????÷????????????????×÷????×???±??　???÷?????‥2?????????????????÷???÷?????????????????????÷???÷???‥?????????????????????÷?????????????　×?????????×??????§?????　±?°??????　???????????????????????????　???????　±????÷?????????????????????????‥2?????　?????　?????????　?????????????÷????×÷????????????????×???????±????????§??×??????　×??÷????

?÷????????
1?????????????÷-????°????????°?　???　?????????　?????　?????÷???????????????　????????±　???×?　?????　????
2?????‥???§??×÷-?　?????　???????????　??????
?　×÷???　??
?????　?????÷?　???　±??　?????÷????±????????????????????????×???????????????????????　????????????????????????????????????????????????????????????????????????±??????　×????????????????????　?　???????????　?????????????÷?????????????????????????????????????????????　?????????????????　??????　??????????　?????????÷???????????????????????±???????　?　??????????????

???????§??
????a???????????????　??????????????????????????????
b????????????×÷???????±????????????×÷???‥???÷??