#include<iostream>
#include<queue>
#include<vector>
#include<algorithm>
using namespace std;
typedef pair<int,int> PII;

int main()
{
    int n;

    while(cin >> n)
    {
        vector<PII> products(n);
        priority_queue<int,vector<int>,greater<int>> small_heap; // 最小堆
        for(int i = 0;i < n;i++)
        {
            cin >> products[i].second >> products[i].first; // 时间+利润
        }
        sort(products.begin(),products.end());
        for(auto p : products)
        {
            small_heap.push(p.second);
            if(p.first < small_heap.size()) small_heap.pop(); // 去除最小值
        }
        int res = 0;
        while(!small_heap.empty())
        {
            res += small_heap.top();
            small_heap.pop();
        }
        cout << res << endl;
    }
    return 0;
}