#include "bits/stdc++.h"
using namespace std;
#define ar array
typedef int64_t ll;
#define int ll
const int N = 1e5 + 5;
const int mod = 1e9 + 7;
int h[N], w[N], pref[N];
int l[N], r[N];
signed main(){
ios::sync_with_stdio(0); cin.tie(0);
int n; cin>>n;
for(int i=1;i<=n;i++){
cin>>h[i];
}
for(int i=1;i<=n;i++){
cin>>w[i];
pref[i] = pref[i-1] + w[i];
}
vector<int> ss;
for(int i=1;i<=n;i++){
while(!ss.empty() && h[ss.back()] > h[i]){
ss.pop_back();
}
if(!ss.empty()) l[i] = ss.back();
else l[i] = 0;
ss.push_back(i);
}
ss.clear();
for(int i=n;i>0;i--){
while(!ss.empty() && h[ss.back()] >= h[i]){
ss.pop_back();
}
if(!ss.empty()) r[i] = ss.back();
else r[i] = n + 1;
}
int res = 0;
for(int i=1;i<=n;i++){
int L = (pref[i-1] - pref[l[i]]) % mod, R = (pref[r[i]-1] - pref[i]) % mod;
int tot = (w[i] * 1ll * (w[i] + 1) / 2 % mod + L * 1ll * R % mod + w[i] * 1ll * (L + R) % mod) % mod;
res = (res + tot * 1ll * (h[i] * 1ll * (h[i] + 1) / 2 % mod)) % mod;
}
cout<<res<<"\n";
}
