"""

"""

import sys
from sys import stdin

N = int(stdin.readline())

A = list(map(int,stdin.readline().split()))

B = list(map(int,stdin.readline().split()))

ba = [ ( A[i] / (0.9999999999999999-B[i]) ,B[i],A[i]) for i in range(N) ]
ba.sort()
ba.reverse()

lv = 1
ans = 0
mod = 10**9+7

for _,b,a in ba:

    ans += lv * a
    ans %= mod

    lv *= b
    lv %= mod

print (ans % mod)