RT，1AC，11WA

#include <bits/stdc++.h>
using namespace std;
struct dat {
  int d, p;
} d[100010];
bool cmp_d(dat &a, dat &b) {return a.d < b.d;}
priority_queue<dat> q;
bool operator < (const dat a, const dat b) {
  return a.p > b.p;
}
int n, tim = 0;
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) {
    scanf("%d%d", &d[i].d, &d[i].p);
  }
  sort(d + 1, d + n + 1, cmp_d);
  q.push(d[1]);
  for (int i = 2; i <= n; i++) {
    dat f = d[i];
    tim += f.d - d[i - 1].d;
    if (tim > 0) {
      q.push(f);
      continue;
    }
    if (q.top().p < f.p) {
      q.pop();
      q.push(f);
    }
  }
  int ans = 0;
  while (!q.empty()) {
    ans += q.top().p;
    q.pop();
  }
  printf("%d\n", ans);
  return 0;
}