#include <bits/stdc++.h>
using namespace std;

int main() {
	int n, tap=0, a=0, b, t=0, x; cin>>n; b=n-1;
	vector<pair<int, int>> anyu(n);
	for(int i=0; i<n; i++){
		cin>>anyu[i].first;
	}
	for(int i=0; i<n; i++){
		cin>>anyu[i].second;
	}
	sort(anyu.begin(), anyu.end());
	while(a<=b){
		
		if(anyu[a].first<=tap){
			t+=anyu[a].second;
			tap+=anyu[a].second;
			a++;
		}
		else{
			while(tap<anyu[a].first-tap){
				if(anyu[b].second==0)
				b--;
				if(anyu[b].second<anyu[a].first-tap){
					t=t+2*anyu[b].second;
					tap+=anyu[b].second;
					anyu[b].second=0;
					b--;					
				}
				else{
					anyu[b].second-=(anyu[a].first-tap);
					t=t+2*(anyu[a].first-tap);
					tap+=anyu[a].first-tap;
						
				}
			}
		}
		/*cerr<<anyu[1].second<<endl;
		cerr<<a<<" "<<b<<" "<<tap<<" "<<t<<endl;*/
	}
	cout<<t;
}