#include <iostream>
#include <vector>
#include <set>
#include <map>
#include <algorithm>
#include <unordered_map>
#include <unordered_set>
#include <iomanip>
#include <deque>
#include <cmath>
#include <array>
#include <random>
#include <cassert>

#define int long long

using namespace std;

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n;
    cin >> n;
    vector<pair<int, int>> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i].first >> a[i].second;
    }
    sort(a.begin(), a.end(), [&] (pair<int, int> p1, pair<int, int> p2) {
        return p1.first > p2.first || (p1.first == p2.first && p1.second < p2.second);
    });
    vector<vector<int>> dp(n + 1, vector<int> (n + 1, 1e16));
    dp[0][0] = 0;
    for (int i = 1; i <= n; i++) {
        for (int j = 0; j < n; j++) {
            dp[i][j + 1] = dp[i - 1][j] + a[i - 1].second;
        }
        for (int j = 0; j <= n; j++) {
            if (n - i + j >= a[i - 1].first) {
                dp[i][j] = min(dp[i][j], dp[i - 1][j]);
            }
        }
    }
    int res = 1e18;
    for (int i = 0; i <= n; i++) {
        res = min(res, dp[n][i]);
    }
    cout << res;
}