#include <bits/stdc++.h>
using namespace std;
struct dian {
  int x, y, i;
} a[1000005];
int m = 0;
void print(int x) {
  if (x < 0) {
    putchar('-');
    x = -x;
  }
  if (x > 9) print(x / 10);
  putchar(x % 10 + '0');
}
inline int read() {
  register int x = 0, ch = getchar();
  while (!isdigit(ch)) ch = getchar();
  while (isdigit(ch)) x = x * 10 + ch - '0', ch = getchar();
  return x;
}
int n, nn;
bool cmp(dian x, dian y) {
  int xl = x.x / nn, yl = y.x / nn;
  if (xl > yl) return 0;
  if (xl < yl) return 1;
  if (xl & 1)
    return x.y > y.y;
  else
    return x.y < y.y;
}
void rd() {
  cin >> n;
  for (int i = 1; i <= n; i++) {
    a[i].x = read();
    a[i].y = read();
    a[i].i = i;
    m = max(m, a[i].x);
    m = max(m, a[i].y);
  }
  nn = sqrt(m) + 1;
  sort(a + 1, a + n + 1, cmp);
}
signed main() {
  rd();
  for (int i = 1; i <= n; i++) {
    print(a[i].i);
    printf(" ");
  }
  return 0;
}

### Prompt

Generate 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;
struct dian {
  int x, y, i;
} a[1000005];
int m = 0;
void print(int x) {
  if (x < 0) {
    putchar('-');
    x = -x;
  }
  if (x > 9) print(x / 10);
  putchar(x % 10 + '0');
}
inline int read() {
  register int x = 0, ch = getchar();
  while (!isdigit(ch)) ch = getchar();
  while (isdigit(ch)) x = x * 10 + ch - '0', ch = getchar();
  return x;
}
int n, nn;
bool cmp(dian x, dian y) {
  int xl = x.x / nn, yl = y.x / nn;
  if (xl > yl) return 0;
  if (xl < yl) return 1;
  if (xl & 1)
    return x.y > y.y;
  else
    return x.y < y.y;
}
void rd() {
  cin >> n;
  for (int i = 1; i <= n; i++) {
    a[i].x = read();
    a[i].y = read();
    a[i].i = i;
    m = max(m, a[i].x);
    m = max(m, a[i].y);
  }
  nn = sqrt(m) + 1;
  sort(a + 1, a + n + 1, cmp);
}
signed main() {
  rd();
  for (int i = 1; i <= n; i++) {
    print(a[i].i);
    printf(" ");
  }
  return 0;
}

```