#include<bits/stdc++.h>
using namespace std;
#define int long long
int h[100007],w[100007];
int l[100007],r[100007];
map<int,int> mx;
const int MOD=1e9+7;
const int INV2=5e8+4;
int get(int a,int b){
return w[b]-w[a-1];
}
int ans(int r,int c){
return (r * (r + 1) % MOD * 500000004 % MOD) * ((c % MOD) * ((c + 1) % MOD) % MOD * 500000004 % MOD) % MOD;
}
signed main(){
ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
int n; cin >> n;
int sum=0;
for(int i=1;i<=n;++i) cin >> h[i];
for(int i=1;i<=n;++i) cin >> w[i],sum+=w[i];
cout << ans(sum,h[1]);
return 0;
stack<int> st;
for(int i=1;i<=n;++i){
while(!st.empty() && h[st.top()]>=h[i]) st.pop();
if(st.empty()) l[i]=1;
else l[i]=st.top()+1;
st.push(i);
}
while(!st.empty()) st.pop();
for(int i=n;i>=1;--i){
while(!st.empty() && h[st.top()]>=h[i]) st.pop();
if(st.empty()) r[i]=n;
else r[i]=st.top()-1;
st.push(i);
}
vector<pair<int,pair<int,int>>> toprocess;
for(int i=1;i<=n;++i){
int bounda=get(1,l[i]-1)+1;
int boundb=get(1,r[i]);
int ha=h[i];
if(boundb==mx[ha]) continue;
mx[ha]=max(mx[ha],boundb);
toprocess.push_back({ha,{bounda,boundb}});
//cout << bounda << " " << boundb << " " << ha << endl;
//cout << ans(boundb-bounda+1,ha)-ans(boundb-bounda+1,prev) << endl;
}
int fans=0;
int prev=0;
sort(toprocess.begin(),toprocess.end());
for(int i=0;i<toprocess.size();++i){
if(i!=0 && toprocess[i].first!=toprocess[i-1].first){
prev=toprocess[i-1].first;
}
fans+=ans(toprocess[i].second.second-toprocess[i].second.first+1,toprocess[i].first);
fans-=ans(toprocess[i].second.second-toprocess[i].second.first+1,prev);
fans+=MOD;
fans%=MOD;
}
cout << fans;
}
