mod = 10 ** 9 + 7


N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))

*idx, = range(N)
idx.sort(key=lambda i: A[i] / (B[i] - 1 + 1e-18))
A = [A[i] for i in idx]
B = [B[i] for i in idx]

ans = 0
L = 1
for a, b in zip(A, B):
    ans += L * a
    ans %= mod
    L = L * b % mod

print(ans)