#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll mod = 1e9+7;
ll const maxn = 1e5+1;
ll pref[maxn];
const ll inv2 = (mod+1)/2;
ll S(ll pret,ll p)
{
ll ans = 0;
ans = (p*(p+1)/2)%mod;
ans -= (pret*(pret+1)/2)%mod;
ans += mod;ans %= mod;
return ans;
}
int main()
{
ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
int n;
cin>>n;
priority_queue<array<ll,2>,vector<array<ll,2> >, greater<array<ll,2> > > pq;
set<int> s;s.insert(0);s.insert(n+1);
vector<ll> v(n+2);v[0] = 0;v[n+1] = 0;
for (int i=1;i<=n;i++)
{
ll a;
cin>>a;
pq.push({a,i});
v[i] = a;
}
for (int i=1;i<=n;i++)
{
ll a;
cin>>a;
pref[i] = pref[i-1] + a;
}
ll odg = 0;
while (pq.size())
{
int p = pq.top()[1];
ll h = pq.top()[0];pq.pop();
auto it = s.lower_bound(p);
int r = *it;it--;int l = *it;
s.insert(p);
//cout<<"p = "<<p<<" l = "<<l<<" r = "<<r<<endl;
ll w = pref[r-1]-pref[l];w%=mod;
//cout<<"w = "<<w<<endl;
ll pret = max(v[l],v[r]);
//cout<<"odg: "<<odg<<endl;
odg += S(0,w) * S(pret,h);
//odg += (((w*(w+1)%mod *inv2)%mod) * ((((h*(h+1)%mod * inv2)%mod) - (pret*(pret+1)%mod *inv2)%mod)%mod))%mod + mod;
///(x * (x + 1) % mod * inv2) % mod
odg%=mod;
//cout<<"odg: "<<odg<<endl;
}
cout<<odg<<endl;
return 0;
}
