�ڸeW(wng)Zo|eôӋ?
1.ڸeW(wng)e(һһθ)
eW(wng)e=2+2L+2L+(L-1)
2.�Zo|e(һһp)
we=L
e=(L+2ߡL)(+2)
Zo|e=we+e=L+(L+2ߡL)(+2)
һ ֙C鿴
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