n = int(input())
a = list(map(int, input().split()))
b = list(map(int, input().split()))
mod = 10**9+7
rab = []
for ai, bi in zip(a, b):
    rab.append(((bi-1)/ai, ai, bi))
rab.sort()
x = 1
ans = 0
for _, ai, bi in rab[::-1]:
    ans = (ans+ai*x)%mod
    x = bi*x%mod
print(ans)