import sys
def input():return sys.stdin.readline().strip()
mod=pow(10,9)+7
n=int(input())
ans,level=0,1
jobs=[[0 for j in range(2)] for i in range(n)]
for i in range(2):
	temp=list(map(int,input().split()))
	for j in range(n):
		jobs[j][i]=temp[j]
jobs=sorted(jobs,key=lambda x:-(x[1]-1)/x[0])
for i in jobs:
	ans=(ans+level*i[0])%mod
	level=(level*i[1])%mod
print(ans)