#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:1024000000")
using namespace std;
const int MAXN = 100100;
const int MAGIC = 1000000 / 1250;
struct N {
  int x, y, id;
  N(int x = 0, int y = 0, int id = 0) : x(x), y(y), id(id){};
};
vector<N> vec[1300];
bool cmp1(N n1, N n2) { return n1.x < n2.x; }
bool cmp2(N n1, N n2) { return n1.x > n2.x; }
int main() {
  int n, i;
  scanf("%d", &n);
  int x, y;
  for (i = 1; i <= n; ++i) {
    scanf("%d %d", &x, &y);
    vec[y / MAGIC].push_back(N(x, y, i));
  }
  for (i = 0; i < 1300; ++i) {
    if (i & 1)
      sort(vec[i].begin(), vec[i].end(), cmp1);
    else
      sort(vec[i].begin(), vec[i].end(), cmp2);
  }
  for (i = 0; i < 1300; ++i) {
    for (vector<N>::iterator it = vec[i].begin(); it != vec[i].end(); ++it) {
      printf("%d\n", it->id);
    }
  }
  return 0;
}

### Prompt

Please create a solution in Cpp 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>
#pragma comment(linker, "/STACK:1024000000")
using namespace std;
const int MAXN = 100100;
const int MAGIC = 1000000 / 1250;
struct N {
  int x, y, id;
  N(int x = 0, int y = 0, int id = 0) : x(x), y(y), id(id){};
};
vector<N> vec[1300];
bool cmp1(N n1, N n2) { return n1.x < n2.x; }
bool cmp2(N n1, N n2) { return n1.x > n2.x; }
int main() {
  int n, i;
  scanf("%d", &n);
  int x, y;
  for (i = 1; i <= n; ++i) {
    scanf("%d %d", &x, &y);
    vec[y / MAGIC].push_back(N(x, y, i));
  }
  for (i = 0; i < 1300; ++i) {
    if (i & 1)
      sort(vec[i].begin(), vec[i].end(), cmp1);
    else
      sort(vec[i].begin(), vec[i].end(), cmp2);
  }
  for (i = 0; i < 1300; ++i) {
    for (vector<N>::iterator it = vec[i].begin(); it != vec[i].end(); ++it) {
      printf("%d\n", it->id);
    }
  }
  return 0;
}

```