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

AB = [(a,b) for a,b in zip(A,B)]
INF = float('inf')
AB.sort(key=lambda x:INF if x[1] == 1 else x[0]/(x[1]-1))
l = 1
ans = 0
for a,b in AB:
    ans += a*l
    ans %= MOD
    l *= b
    l %= MOD
print(ans)