#include <bits/stdc++.h>
using namespace std;
struct query {
  int l, r, id;
} a[1000010];
int n, i, b[1000010], gap;
int read() {
  char c = getchar();
  int w = 0;
  while (c < '0' || c > '9') c = getchar();
  while (c <= '9' && c >= '0') {
    w = w * 10 + c - '0';
    c = getchar();
  }
  return w;
}
int my_comp(const query &x, const query &y) {
  if (b[x.l] == b[y.l]) {
    if (b[x.l] % 2 == 0)
      return x.r < y.r;
    else
      return x.r > y.r;
  }
  return x.l < y.l;
}
int main() {
  n = read();
  gap = sqrt(1.0 * n);
  for (i = 1; i <= 1000001; i++) b[i] = (i - 1) / gap + 1;
  for (i = 1; i <= n; i++) {
    a[i].l = read() + 1, a[i].r = read() + 1;
    a[i].id = i;
  }
  sort(a + 1, a + n + 1, my_comp);
  for (i = 1; i <= n; i++) printf("%d ", a[i].id);
  puts("");
  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>
using namespace std;
struct query {
  int l, r, id;
} a[1000010];
int n, i, b[1000010], gap;
int read() {
  char c = getchar();
  int w = 0;
  while (c < '0' || c > '9') c = getchar();
  while (c <= '9' && c >= '0') {
    w = w * 10 + c - '0';
    c = getchar();
  }
  return w;
}
int my_comp(const query &x, const query &y) {
  if (b[x.l] == b[y.l]) {
    if (b[x.l] % 2 == 0)
      return x.r < y.r;
    else
      return x.r > y.r;
  }
  return x.l < y.l;
}
int main() {
  n = read();
  gap = sqrt(1.0 * n);
  for (i = 1; i <= 1000001; i++) b[i] = (i - 1) / gap + 1;
  for (i = 1; i <= n; i++) {
    a[i].l = read() + 1, a[i].r = read() + 1;
    a[i].id = i;
  }
  sort(a + 1, a + n + 1, my_comp);
  for (i = 1; i <= n; i++) printf("%d ", a[i].id);
  puts("");
  return 0;
}

```