#include <bits/stdc++.h>

using namespace std;

int main()
{
    int n;
    int ido = 0;
    cin >> n;
    vector<pair<int, int>> v(n);
    for (int i = 0; i < n; i ++) {
        cin >> v[i].first;
    }
    int kellmeg = 0;
    for (int i = 0; i < n; i ++) {
        cin >> v[i].second;
        kellmeg += v[i].second;
    }
    sort(v.begin(), v.end());
    int exp = 0;
    int pici = 0;
    int nagy = n - 1;
    while (kellmeg != 0) {
        if (exp >= v[pici].first) {
            v[pici].second -= 1;
            ido += 1;
            exp += 1;
            kellmeg -= 1;
            if (v[pici].second == 0) pici += 1;
        } else {
            v[nagy].second -= 1;
            ido += 2;
            exp += 1;
            kellmeg -= 1;
            if (v[nagy].second == 0) nagy -= 1;
        }
    }
    cout << ido;
    return 0;
}