#include <bits/stdc++.h>
using namespace std;

struct node {
  int a, b;
};

bool cmp(const node& A, const node& B) {
  if (A.b != B.b) return A.b > B.b;
  return A.a > B.a;
}

int main() {
  int n;
  cin >> n;
  vector<node> V(n);
  for (auto& v : V) cin >> v.a >> v.b;
  sort(begin(V), end(V), cmp);
  int ans = 0, l = 1, pos = 0;
  while (l != 0) {
    ans += V[pos].a;
    l += V[pos++].b - 1;
  }
  cout << ans;
  return 0;
}