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

int main()
{
    int n;
    cin >> n;
    vector<pair<long long, long long>> v(n);

    for (int i=0; i < n; i++) {
        cin >> v[i].first;
    }
    long long total = 0;
    for (int i=0; i < n; i++) {
        cin >> v[i].second;
        total += v[i].second;
    }

    sort(v.begin(), v.end());

    long long mined = 0;
    long long res = 0;

    int i=0;

    while (total > 0) {
        long long needed_xp_for_left = max(0LL, v[i].first - mined);
        if (needed_xp_for_left >= total) {
            res += 2 * total;
            mined += total;
            total = 0;
        } else {
            res += 2 * needed_xp_for_left;
            mined += needed_xp_for_left;
            total -= needed_xp_for_left;
            mined += min(total, v[i].second);
            res += min(total, v[i].second);
            total -= min(total, v[i].second);
        }
        i++;
    }

    cout << res << '\n';

    return 0;
}