#include<bits/stdc++.h>
#define int long long
using namespace std;
int h[100005];
int w[100005];
int sumhw;
int md=1e9+7;
int calc(int h,int w){
return ((h*(h+1)/2)%md*((w*(w+1)/2)%md))%md;
}
int32_t main(){
ios_base::sync_with_stdio(false);
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];
stack<pair<int,int>>s;
int ans=0;
//cerr<<"work\n";
for(int i=1;i<=n;i++){
int curw=w[i];
while(!s.empty()&&h[i]<s.top().first){
auto [x,ww]=s.top();
int temp=(s.top().first*(s.top().first+1)/2)%md;
sumhw=(sumhw-((temp*ww)%md)+md)%md;
curw=(curw+ww)%md;
s.pop();
}
int temp=(w[i]*(w[i]+1)/2)%md;
int temp2=(h[i]*(h[i]+1)/2)%md;
ans=(ans+w[i]*sumhw)%md;
ans=(ans+calc(h[i],w[i]))%md;
ans=(ans+((temp2*w[i])%md*(curw-w[i])))%md;
s.push({h[i],curw});
sumhw=(sumhw+(temp2*curw)%md)%md;
//cerr<<ans<<"\n";
}
cout<<ans;
}
