#!/usr/bin/env PyPy3

from collections import Counter, defaultdict, deque
import itertools
import re
import math
from functools import reduce
import operator
import bisect
from heapq import *
import functools
mod=10 ** 9 + 7

import sys
input=sys.stdin.readline

n = int(input())
a = list(map(int,input().split()))
b = list(map(int,input().split()))
ab = []
c = []
for i in range(n):
    if b[i] != 1:
        ab.append([a[i],b[i]])
    else:
        c.append([a[i],b[i]])
    
ab.sort(key = lambda x:x[0]/(x[1] - 1))

ans = 0
now = 1
for a,b in ab:
    ans += now * a
    ans %= mod
    now *= b
    now %= mod
for a,b in c:
    ans += now * a
    ans %= mod
    now *= b
    now %= mod
print(ans)