#include <bits/stdc++.h>
using namespace std;
#define int long long
const int N=1e5+37;
int p[N], vis[N], length[N];
int sum, ans=0, mod=1e9+7;
int s(int x, int y){
return ((x+y)%mod+mod)%mod;
}
int mul(int x, int y){
return (x*y)%mod;
}
int poww(int x, int y){
if(y==0) return 1;
int tmp=poww(x, y/2);
if(y&1) return mul(tmp, mul(tmp, x));
return mul(tmp, tmp);
}
int val(int x){
return mul(mul(x, (x+1)), poww(2, mod-2));
}
int find(int x){
return (p[x]!=x)?p[x]=find(p[x]):x;
}
void dsu(int x, int y){
x=find(x);
y=find(y);
if(x==y) return;
sum=s(sum, -val(length[x]));
sum=s(sum, -val(length[y]));
p[y]=x;
length[x]=s(length[x], length[y]);
sum=s(sum, val(length[x]));
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
int n; cin>>n;
vector<array<int, 3>> a(n+1);
for(int i=1; i<=n; i++) p[i]=i;
for(int i=0; i<n; i++){
cin>>a[i][0];
a[i][2]=i+1;
}
for(int i=0; i<n; i++){
cin>>a[i][1];
length[i+1]=a[i][1];
}
sort(a.begin(), a.end());
reverse(a.begin(), a.end());
for(int i=0; i<a.size()-1; i++)
{
int p=a[i][2], len=a[i][1], h=a[i][0];
sum=s(sum, val(length[p])); vis[p]=1;
if(vis[p-1]&&vis[p+1]){
dsu(p, p-1);
dsu(p, p+1);
}
else if(vis[p-1]){
dsu(p, p-1);
}
else if(vis[p+1]){
dsu(p, p+1);
}
ans=s(ans, mul(sum, s(val(h), -val(a[i+1][0]))));
}
cout<<ans;
}
