#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint1000000007;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000001

int main(){
	
	int n;
	cin>>n;
	vector<long long> a(n),b(n);
	vector<int> t(n);
	rep(i,n){
		cin>>a[i];
		t[i] = i;
	}
	rep(i,n)cin>>b[i];
	
	sort(t.begin(),t.end(),[&](int x,int y){
		return a[x]*(b[y]-1)<a[y]*(b[x]-1);
	});
	
	mint x = 1;
	mint ans = 0;
	rep(i,n){
		ans += x * a[t[i]];
		x *= b[t[i]];
	}
	cout<<ans.val()<<endl;
	
    return 0;
}