from heapq import *

N = int(input())
P = list(map(int, input().split()))
Q = list(map(int, input().split()))

H = []
ans = 0
for i in range(N):
    heappush(H, (-P[i] * Q[i]/1e5, 1 - Q[i]/1e2))
    
for i in range(1, 10**6):
    v, q = heappop(H)
    ans -= v * i
    v *= q
    heappush(H, (v, q))
    
print(ans)