TASK B

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <ctime>
#include <cstring>
#include <string>
#include <queue>
#include <set>
#include <map>
#include <vector>
#include <algorithm>
#include <cmath>

using namespace std;

typedef unsigned long long ull;

const int MAXN=111111;

int n,i,j,x,t;

pair<int,int> a[MAXN];

set<int> f;

int main()
{
    freopen("jumps.in","r",stdin);
    freopen("jumps.out","w",stdout);

    cin >> n;

    for (i=0;i<n;i++) {
        cin >> x >> t;
        a[i]=make_pair(x,t);
    }

    sort(a,a+n);

    reverse(a,a+n);
    for (i=1;i<=n;i++)
        f.insert(i);
    long long ans=0;
    for (i=0;i<n;i++) {
        int pos=a[i].second+1;
        set<int>::iterator it = f.lower_bound(pos);
        if (it==f.end()) {
            ans+=(long long)a[i].first;
        }
        else {
            f.erase(it);
        }
    }

    cout << ans << '\n';

    return 0;
}