#include<bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define pb push_back
using namespace std;
ll const mod=1e9+7;
int n,h[100005],w[100005];
ll tw[400005],ans;
pair<int,int> th[400005];
void build(int id,int l,int r)
{
if(l==r)
{
th[id]={h[l],l};
tw[id]=w[l];
return;
}
int mid=(l+r)/2;
build(id*2,l,mid);
build(id*2+1,mid+1,r);
tw[id]=tw[id*2]+tw[id*2+1];
tw[id]%=mod;
th[id]=min(th[id*2],th[id*2+1]);
}
pair<int,int> geth(int id,int l,int r,int u,int v)
{
if(r<u||v<l) return {1e9+9,1e9+9};
if(u<=l&&r<=v)
{
return th[id];
}
int mid=(l+r)/2;
return min(geth(id*2,l,mid,u,v),geth(id*2+1,mid+1,r,u,v));
}
ll getw(int id,int l,int r,int u,int v)
{
if(r<u||v<l) return 0;
if(u<=l&&r<=v)
{
return tw[id];
}
int mid=(l+r)/2;
return (getw(id*2,l,mid,u,v)+getw(id*2+1,mid+1,r,u,v))%mod;
}
ll get(ll x,ll y)
{
return (x*(x+1)/2%mod)%mod*(y*(y+1)/2%mod)%mod;
}
void solve(int l,int r)
{
if(r<l) return;
pair<int,int> p=geth(1,1,n,l,r);
ll hh=p.fi,id=p.se;
ll a=getw(1,1,n,l,id-1),b=w[id],c=getw(1,1,n,id+1,r);
ll sum=a+b+c;
ll val=(( get(hh,sum) - get(hh,a) - get(hh,c) )%mod+mod)%mod;
ans+=val;
ans%=mod;
solve(l,id-1);
solve(id+1,r);
}
int main()
{
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
// freopen(".inp","r",stdin);
// freopen(".out","w",stdout);
cin>>n;
for(int i=1;i<=n;i++)
{
cin>>h[i];
}
for(int i=1;i<=n;i++)
{
cin>>w[i];
}
build(1,1,n);
solve(1,n);
cout<<ans;
}
