#include <bits/stdc++.h>
using namespace std;
int main() {
  std::ios::sync_with_stdio(false);
  cin.tie(NULL);
  int n;
  cin >> n;
  vector<tuple<int, int, int> > pts;
  for (int i = 0; i < n; i++) {
    int x, y;
    cin >> x >> y;
    pts.push_back(make_tuple(i + 1, x, y));
  }
  std::sort(begin(pts), end(pts),
            [](tuple<int, int, int> const &t1, tuple<int, int, int> const &t2) {
              int slot1 = get<1>(t1) == 1000000 ? 999 : get<1>(t1) / 1000;
              int slot2 = get<1>(t2) == 1000000 ? 999 : get<1>(t2) / 1000;
              if (slot1 != slot2) {
                return slot1 < slot2;
              }
              if (slot1 % 2 != 0) {
                return get<2>(t1) > get<2>(t2);
              }
              return get<2>(t1) < get<2>(t2);
            });
  vector<int> res;
  for (auto t : pts) {
    cout << get<0>(t) << " ";
  }
}

### Prompt

Your challenge is to write a CPP solution to the following problem:

On a plane are n points (xi, yi) with integer coordinates between 0 and 106. The distance between the two points with numbers a and b is said to be the following value: <image> (the distance calculated by such formula is called Manhattan distance).

We call a hamiltonian path to be some permutation pi of numbers from 1 to n. We say that the length of this path is value <image>.

Find some hamiltonian path with a length of no more than 25 × 108. Note that you do not have to minimize the path length.

Input

The first line contains integer n (1 ≤ n ≤ 106).

The i + 1-th line contains the coordinates of the i-th point: xi and yi (0 ≤ xi, yi ≤ 106).

It is guaranteed that no two points coincide.

Output

Print the permutation of numbers pi from 1 to n — the sought Hamiltonian path. The permutation must meet the inequality <image>.

If there are multiple possible answers, print any of them.

It is guaranteed that the answer exists.

Examples

Input

5
0 7
8 10
3 4
5 0
9 12


Output

4 3 1 2 5 

Note

In the sample test the total distance is:

<image>

(|5 - 3| + |0 - 4|) + (|3 - 0| + |4 - 7|) + (|0 - 8| + |7 - 10|) + (|8 - 9| + |10 - 12|) = 2 + 4 + 3 + 3 + 8 + 3 + 1 + 2 = 26

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
int main() {
  std::ios::sync_with_stdio(false);
  cin.tie(NULL);
  int n;
  cin >> n;
  vector<tuple<int, int, int> > pts;
  for (int i = 0; i < n; i++) {
    int x, y;
    cin >> x >> y;
    pts.push_back(make_tuple(i + 1, x, y));
  }
  std::sort(begin(pts), end(pts),
            [](tuple<int, int, int> const &t1, tuple<int, int, int> const &t2) {
              int slot1 = get<1>(t1) == 1000000 ? 999 : get<1>(t1) / 1000;
              int slot2 = get<1>(t2) == 1000000 ? 999 : get<1>(t2) / 1000;
              if (slot1 != slot2) {
                return slot1 < slot2;
              }
              if (slot1 % 2 != 0) {
                return get<2>(t1) > get<2>(t2);
              }
              return get<2>(t1) < get<2>(t2);
            });
  vector<int> res;
  for (auto t : pts) {
    cout << get<0>(t) << " ";
  }
}

```