#include <bits/stdc++.h>
using namespace std;
#define forn(i,n) for(int i=0;i<int(n);i++)
#define forsn(i,s,n) for(int i=int(s);i<int(n);i++)
#define dforn(i,n) for(int i=int(n)-1;i>=0;i--)
#define dforsn(i,s,n) for(int i=int(n)-1;i>=int(s);i--)
#define fst first
#define snd second
#define pb push_back
#define eb emplace_back
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
typedef long long ll;
typedef vector<ll> vll;
typedef vector<int> vi;
typedef pair<int,int> ii;
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
int n;
cin>>n;
map<int,int> x,y;
forn(i,n) cin>>x[i];
forn(i,n) cin>>y[i];
ll score=0;
forn(i,n){
if(!y.count(i)) continue;
while(y[i]>0){
auto it=x.lower_bound(i);
if(it!=x.begin()){
it--;
if(it->snd<=y[i]){
y[i]-=it->snd;
score+=it->snd;
x.erase(it);
}else{
score+=y[i];
it->snd-=y[i];
y[i]=0;
}
}else break;
}
if(y[i]==0) y.erase(i);
}
forn(i,n){
if(!y.count(i)) continue;
auto it=x.lower_bound(i);
if(it->fst==i){
if(it->snd<=y[i]){
y[i]-=it->snd;
x.erase(it);
}else{
it->snd-=y[i];
y[i]=0;
}
}
score-=y[i];
}
cout<<score<<'\n';
return 0;
}
