#include <bits/stdc++.h>
using namespace std;
inline int read() {
  int x = 0, f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = x * 10 + ch - '0';
    ch = getchar();
  }
  return x * f;
}
int n;
const int maxn = 1000007;
pair<int, pair<int, int> > Q[maxn];
int main() {
  n = read();
  for (int i = 1; i <= n; i++) {
    Q[i].first = read() / 1050;
    Q[i].second.first = read();
    Q[i].second.second = i;
  }
  sort(Q + 1, Q + 1 + n);
  for (int i = 1; i <= n; i++) cout << Q[i].second.second << " ";
  cout << endl;
}
