#include <bits/stdc++.h>
using namespace std;
int const MAX=100005;
int const MOD=1000000007;
int const INV2=500000004;
int h[MAX],w[MAX];
int n;
int ans;
struct info{
int len,h,total;
};
void read(){
cin>>n;
int i;
for(i=1;i<=n;++i)
cin>>h[i];
for(i=1;i<=n;++i)
cin>>w[i];
}
void aduna(int& x,int val){
x=(x+val)%MOD;
}
void solve(){
stack<info>stv;
int i;
for(i=1;i<=n;++i){
aduna(ans,1LL*w[i]*(w[i]+1)%MOD*INV2%MOD*h[i]%MOD*(h[i]+1)%MOD*INV2%MOD);
int len=0;
while(!stv.empty() && stv.top().h>h[i]){
aduna(len,stv.top().len);
stv.pop();
}
aduna(ans,1LL*w[i]*len%MOD*h[i]%MOD*(h[i]+1)%MOD*INV2%MOD);
if(!stv.empty())
aduna(ans,1LL*w[i]*stv.top().total%MOD);
aduna(len,w[i]);
int total=1LL*len*h[i]%MOD*(h[i]+1)%MOD*INV2%MOD;
if(!stv.empty())
aduna(total,stv.top().total);
stv.push({len,h[i],total});
}
}
int main()
{
read();
solve();
cout<<ans;
return 0;
}
