N = int(input())
A = list(map(int,input().split()))
B = list(map(int,input().split()))
mod = 10**9+7

C = []

for i in range(N):
    tmp = (B[i]-1)/A[i]
    C.append([tmp,i])

C.sort()
C.reverse()

level = 1
ans = 0

for i,ii in C:
    ans+=level*A[ii]
    ans = ans%mod
    level*=B[ii]

print(ans)