#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main() {
	int n;
	cin >> n;
	vector<pair<int, int>> data(n);
	for (int i = 0; i < n; i++) cin >> data[i].first;
	for (int i = 0; i < n; i++) cin >> data[i].second;
	sort(data.begin(), data.end());
	int ptr1 = 0, ptr2 = n - 1, t = 0, e = 0;
	while (ptr1 != ptr2) {
		if (e >= data[ptr1].first) {
			t += data[ptr1].second;
			e += data[ptr1].second;
			ptr1++;
			continue;
		}
		if (data[ptr1].first - e < data[ptr2].second) {
			data[ptr2].second -= data[ptr1].first - e;
			t += (data[ptr1].first - e) * 2;
			e += data[ptr1].first - e;
			continue;
		}
		e += data[ptr2].second;
		t += data[ptr2].second * 2;
		ptr2--;
	}
	int diff = max(0, data[ptr1].second - data[ptr1].first + e);
	t += diff;
	t += 2 * (data[ptr1].second - diff);
	cout << t;
	return 0;
}