#include <bits/stdc++.h>
using namespace std;
const int inf = (1 << 30) - 1;
const long long linf = (1ll << 62) - 1;
const int C = 3001;
int main() {
  int n;
  cin >> n;
  vector<pair<pair<int, int>, int>> points(n);
  for (int i = 0; i < n; i++) {
    scanf("%d%d", &points[i].first.first, &points[i].first.second);
    points[i].second = i;
    points[i].first.first /= C;
  }
  sort((points).begin(), (points).end(),
       [](const pair<pair<int, int>, int> &a,
          const pair<pair<int, int>, int> &b) {
         return a.first.first < b.first.first ||
                (a.first.first == b.first.first &&
                 (a.first.first % 2 == 0 ? (a.first.second < b.first.second)
                                         : (a.first.second > b.first.second)));
       });
  for (auto i : points) {
    printf("%d ", i.second + 1);
  }
  puts("");
  return 0;
}

### Prompt

Your task is to create 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;
const int inf = (1 << 30) - 1;
const long long linf = (1ll << 62) - 1;
const int C = 3001;
int main() {
  int n;
  cin >> n;
  vector<pair<pair<int, int>, int>> points(n);
  for (int i = 0; i < n; i++) {
    scanf("%d%d", &points[i].first.first, &points[i].first.second);
    points[i].second = i;
    points[i].first.first /= C;
  }
  sort((points).begin(), (points).end(),
       [](const pair<pair<int, int>, int> &a,
          const pair<pair<int, int>, int> &b) {
         return a.first.first < b.first.first ||
                (a.first.first == b.first.first &&
                 (a.first.first % 2 == 0 ? (a.first.second < b.first.second)
                                         : (a.first.second > b.first.second)));
       });
  for (auto i : points) {
    printf("%d ", i.second + 1);
  }
  puts("");
  return 0;
}

```