MOD = 10 ** 9 + 7

class f:
    def __init__(self, a, b):
        self.a = a
        self.b = b
    
    def __lt__(self, other):
        return (1 - self.b) * other.a < (1 - other.b) * self.a


n = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
ab = [f(a, b) for a, b in zip(A, B)]
ab.sort()
x = 1
ans = 0
for tmp in ab:
    a = tmp.a
    b = tmp.b
    ans += a * x
    ans %= MOD
    x *= b
    x %= MOD
print(ans)