#include <bits/stdc++.h>
using namespace std;
int BLOCK = 1000;
const int N = 1000001;
pair<pair<long long, long long>, long long> arr[N];
pair<pair<long long, long long>, long long> brr[N];
bool comp(const pair<pair<long long, long long>, long long> a,
          const pair<pair<long long, long long>, long long> b) {
  if ((a.first.first / BLOCK) == (b.first.first / BLOCK)) {
    return a.first.second < b.first.second;
  } else {
    return (a.first.first / BLOCK) < (b.first.first / BLOCK);
  }
}
int main(void) {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> arr[i].first.first >> arr[i].first.second;
    arr[i].second = i + 1;
    if (((arr[i].first.first / BLOCK) % 2)) arr[i].first.second *= -1;
  }
  sort(arr, arr + n, comp);
  for (int i = 0; i < n; i++) {
    cout << arr[i].second << " ";
  }
  return 0;
}

### Prompt

Create a solution in Cpp for 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 BLOCK = 1000;
const int N = 1000001;
pair<pair<long long, long long>, long long> arr[N];
pair<pair<long long, long long>, long long> brr[N];
bool comp(const pair<pair<long long, long long>, long long> a,
          const pair<pair<long long, long long>, long long> b) {
  if ((a.first.first / BLOCK) == (b.first.first / BLOCK)) {
    return a.first.second < b.first.second;
  } else {
    return (a.first.first / BLOCK) < (b.first.first / BLOCK);
  }
}
int main(void) {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> arr[i].first.first >> arr[i].first.second;
    arr[i].second = i + 1;
    if (((arr[i].first.first / BLOCK) % 2)) arr[i].first.second *= -1;
  }
  sort(arr, arr + n, comp);
  for (int i = 0; i < n; i++) {
    cout << arr[i].second << " ";
  }
  return 0;
}

```