#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pll pair<int, int>
#define mp make_pair
#define pb push_back
#define f first
#define s second
#define endl '\n'
#define ld long double
#define sz(x) static_cast<int>((x).size())
#define i5 tuple<int,int,int,int,int>
int ans=0;
const int mod=1e9+7;
signed main(){
int n;cin>>n;
vector<int> h(n+1, 0), w(n+1, 0);
for(int i=1;i<=n;i++)cin>>h[i];
for(int i=1;i<=n;i++)cin>>w[i];
for(int i=1;i<=n;i++){
ans=(ans+(h[i]*h[i]+h[i])/2%mod * ((w[i]*w[i]+w[i])/2%mod))%mod;
}
vector<tuple<int,int,int>> v;
for(int i=1;i<=n;i++){
int sm=0;
while(!v.empty() and get<0>(v.back()) >= h[i]){
sm+=get<1>(v.back());
v.pop_back();
}
int rem=(v.empty() ? 0 : get<2>(v.back()));
int pop=sm*((h[i]*h[i]+h[i])/2%mod)%mod;
ans=(ans+(rem+pop)*w[i]%mod)%mod;
sm=(sm+w[i])%mod;
int topans=rem+sm*((h[i]*h[i]+h[i])/2%mod)%mod;
v.push_back({sm, h[i], topans});
}
cout<<ans;
}
