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


class D:
    def __init__(self, a, b):
        self.a = a
        self.b = b
        self.key = (b - 1) / a


ds = [D(a, b) for a, b in zip(A, B)]
x = 1
ans = 0
for d in sorted(ds, key=lambda x: x.key, reverse=True):
    ans += d.a * x
    ans %= MOD
    x *= d.b
    x %= MOD

print(ans)