On a plane are *n* points (*x*<sub class="lower-index">*i*</sub>, *y*<sub class="lower-index">*i*</sub>) with integer coordinates between 0 and 10<sup class="upper-index">6</sup>. The distance between the two points with numbers *a* and *b* is said to be the following value: <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/03274f8c977ad3feb5d9f6ede91c69bcaef04972.png" style="max-width: 100.0%;max-height: 100.0%;"/> (the distance calculated by such formula is called Manhattan distance).

We call a hamiltonian path to be some permutation *p*<sub class="lower-index">*i*</sub> of numbers from 1 to *n*. We say that the length of this path is value <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/2872e932e7cab8f5f7a9c718441f7534261ed638.png" style="max-width: 100.0%;max-height: 100.0%;"/>.

Find some hamiltonian path with a length of no more than 25 × 10<sup class="upper-index">8</sup>. Note that you do not have to minimize the path length.
The first line contains integer *n* (1 ≤ *n* ≤ 10<sup class="upper-index">6</sup>).

The *i* + 1-th line contains the coordinates of the *i*-th point: *x*<sub class="lower-index">*i*</sub> and *y*<sub class="lower-index">*i*</sub> (0 ≤ *x*<sub class="lower-index">*i*</sub>, *y*<sub class="lower-index">*i*</sub> ≤ 10<sup class="upper-index">6</sup>).

It is guaranteed that no two points coincide.
import sys
input = sys.stdin.readline
n = int(input())
a = []
for i in range(n):
    x, y = [int(xx) for xx in input().split()]
    a.append((10000 * x + 2000 * y, i))
a = sorted(a)
for i in range(n):
    print(a[i][1] + 1, end = ' ')
