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


def key(x):
    a, b = x
    return (b - 1) / a


xs = list(zip(A, B))

x = 1
ans = 0
for a, b in sorted(xs, key=key, reverse=True):
    ans += a * x
    ans %= MOD
    x *= b
    x %= MOD

print(ans)