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

AB = list(zip(A, B))
AB.sort(key = lambda x:(1-x[1])/x[0])

level = 1
salary = 0
for Ai, Bi in AB:
    salary += Ai*level
    salary %= mod
    level *= Bi
    level %= mod

print(salary)