// Bányász RPG.cpp : This file contains the 'main' function. Program execution begins and ends there.
//

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int n;
    cin >> n;
    vector<pair<int, int>> anyag(n);
    for (int i = 0; i < n; i++)
    {
        cin >> anyag[i].first;
    }
    for (int i = 0; i < n; i++)
    {
        cin >> anyag[i].second;
    }
    sort(anyag.begin(), anyag.end(),[](auto s1, auto s2){
        return s1.second < s2.second;
    });
    int i = 0;
    int j = n-1;
    long long ido = 0;
    long long exp = 0;
    while (i <= j)
    {
        if ( exp >= anyag[i].second)
        {
            exp += anyag[i].first;
            ido += anyag[i].first;
                i++;
        }
        else {
            long long kell = anyag[i].second - exp;
            if (kell >= anyag[j].first)
            {
                exp += anyag[j].first;
                ido += 2 * anyag[j].first;
                j--;
            }
            else
            {
                exp += kell;
                ido += 2 * kell;
                anyag[j].first -= kell;
            }
        }
        
    }
    cout << ido;
}

// Run program: Ctrl + F5 or Debug > Start Without Debugging menu
// Debug program: F5 or Debug > Start Debugging menu

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