N = int(input())
A = list(map(int,input().split()))
B = list(map(int,input().split()))
P = 10 ** 9 + 7
inf = 10 ** 9
def f(x):
    a,b = x
    if b == 1:
        return inf
    else:
        return a / (b - 1)
C = [(a,b) for a,b in zip(A,B)]
C.sort(key = f)
ans = 0
now = 1
for a,b in C:
    ans += a * now
    ans %= P
    now = now * b % P
print(ans)