#include <cstdio>
#include <stdio.h>
#include <stdbool.h>
#include <iostream>
#include <map>
#include <vector>
#include <climits>
#include <stack>
#include <string>
#include <queue>
#include <algorithm>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <cmath>
#include <cctype>
#include <bitset>
#include <iomanip>
#include <cstring>
#include <numeric>
#include <cassert>
#include <random>
using namespace std;
#define int long long
#define pii pair<int, int>
#define mp make_pair
#define pb push_back
#define fi first
#define se second
const int MOD = 1000000007;
int inv(int num){
int p=MOD, res=1, y=0;
while (num>1){
int q=num/p, t=p;
p=num%p, num=t, t=y, y=res-q*y, res=t;
}
if (res<0)res+=MOD;
return res;
}
int32_t main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n, ans=0;
cin>>n;
vector<pii> vect(n);
for (int i=0; i<n; ++i)cin>>vect[i].fi;
for (int i=0; i<n; ++i)cin>>vect[i].se;
deque<pii> deq;
for (int i=0; i<n; ++i){
ans=(ans+((((((vect[i].fi*(vect[i].fi+1))%MOD)*vect[i].se)%MOD)*(vect[i].se+1))%MOD)*inv(4))%MOD;
for (auto c:deq)ans=(ans+((((((vect[i].se*c.se)%MOD)*min(vect[i].fi, c.fi))%MOD)*(min(vect[i].fi, c.fi)+1))%MOD)*inv(2))%MOD;
int w=vect[i].se;
while (deq.size()&&deq.back().fi>=vect[i].fi)w+=deq.back().se, deq.pop_back();
deq.pb(mp(vect[i].fi, w%MOD));
}
cout<<ans;
}
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