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

job_weight = []
for i in range(n):
	job_weight.append(((B[i]-1)/A[i],i))
job_weight.sort(reverse=True)

money = 0
job_power = 1
for _,job in job_weight:
	money += A[job]*job_power
	money %= MOD
	job_power *= B[job]
print(money)