#include <bits/stdc++.h>
using namespace std;
int read() {
  int ans = 0;
  char last = ' ', ch = getchar();
  while (ch < '0' || ch > '9') last = ch, ch = getchar();
  while (ch >= '0' && ch <= '9') ans = ans * 10 + ch - '0', ch = getchar();
  if (last == '-') ans = -ans;
  return ans;
}
const int N = 100009;
int k = (int)sqrt(1000000);
struct node {
  int x, y, id;
  bool operator<(const node a) const {
    if (x / k != a.x / k) return x / k < a.x / k;
    if ((x / k) % 2) return y > a.y;
    return y < a.y;
  }
} e[1000009];
int main() {
  int n = read();
  for (int i = 1; i <= n; i++) {
    scanf("%d%d", &e[i].x, &e[i].y);
    e[i].id = i;
  }
  sort(e + 1, e + 1 + n);
  for (int i = 1; i <= n; i++) {
    printf("%d ", e[i].id);
  }
  printf("\n");
}

### 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 read() {
  int ans = 0;
  char last = ' ', ch = getchar();
  while (ch < '0' || ch > '9') last = ch, ch = getchar();
  while (ch >= '0' && ch <= '9') ans = ans * 10 + ch - '0', ch = getchar();
  if (last == '-') ans = -ans;
  return ans;
}
const int N = 100009;
int k = (int)sqrt(1000000);
struct node {
  int x, y, id;
  bool operator<(const node a) const {
    if (x / k != a.x / k) return x / k < a.x / k;
    if ((x / k) % 2) return y > a.y;
    return y < a.y;
  }
} e[1000009];
int main() {
  int n = read();
  for (int i = 1; i <= n; i++) {
    scanf("%d%d", &e[i].x, &e[i].y);
    e[i].id = i;
  }
  sort(e + 1, e + 1 + n);
  for (int i = 1; i <= n; i++) {
    printf("%d ", e[i].id);
  }
  printf("\n");
}

```