#include <bits/stdc++.h>

using namespace std;
#define rep(i,n) for(int i=0;i<n;++i)
#define rep1(i,n) for(int i=1;i<=n;++i)
#define rrep(i,n) for(int i=n-1;i>=0;--i)
#define debug(output) if(debugFlag)cout<<#output<<"= "<<output<<"\n";
using lint = long long;
typedef pair<int,int> P;
const bool debugFlag=true;
const lint linf=1.1e18;const int inf=1.01e9;
constexpr int MOD=1000000007;
template<class T>bool chmax(T &a, const T &b) { if(a < b){ a = b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if(a > b){ a = b; return 1; } return 0; }

#include<atcoder/all>
using namespace atcoder;
using mint = modint1000000007;

bool compare(array<lint,2> x,array<lint,2> y){
    auto [a1,b1]=x;auto [a2,b2]=y;
    return a2*(b1-1)-a1*(b2-1)>0; 
}

signed main(){
    int n;cin>>n;
    vector<array<lint,2>> a(n);
    rep(j,2)rep(i,n)cin>>a[i][j];
    sort(a.begin(),a.end(),compare);
    mint res=0;
    mint p=1;
    rep(i,n){
        auto [x,y]=a[i];
        res+=p*x;
        p*=y;
    }
    cout<<res.val()<<"\n";
    return 0;
}