#include <bits/stdc++.h>
using namespace std;
int n, m;
vector<int> g[100001], vc;
int judge(int x) {
  vc.clear();
  int need = x - g[0].size(), ans = 0;
  for (int i = 1; i < 100001; i++) {
    for (int j = 0; j < g[i].size(); j++) {
      if (g[i].size() - j >= x) {
        need--;
        ans += g[i][j];
      } else
        vc.push_back(g[i][j]);
    }
  }
  sort(vc.begin(), vc.end());
  for (int i = 0; i < need; i++) ans += vc[i];
  return ans;
}
int main() {
  scanf("%d", &n);
  int a, b;
  for (int i = 0; i < n; i++) {
    scanf("%d%d", &a, &b);
    g[a].push_back(b);
  }
  for (int i = 1; i < 100001; i++) {
    sort(g[i].begin(), g[i].end());
  }
  int l = g[0].size(), r = n;
  while (l < r) {
    int mid = (l + l + r) / 3, mmid = (l + r + r) / 3;
    if (judge(mid) > judge(mmid)) {
      if (l == mid)
        break;
      else
        l = mid;
    } else {
      if (r == mmid)
        break;
      else
        r = mmid;
    }
  }
  int ans = 0x3f3f3f3f;
  for (int i = l; i <= r; i++) ans = min(ans, judge(i));
  printf("%d\n", ans);
}
