#include <bits/stdc++.h>
using namespace std;
using LD = long double;
using PLL = pair<long long, long long>;
template <class T>
bool power_2(T v) {
  static_assert(std::is_integral<T>::value, "type should be integral");
  return v && !(v & (v - 1));
}
template <class T>
istream& operator>>(istream& st, vector<T>& container) {
  for (auto& u : container) st >> u;
  return st;
}
template <class T, size_t N>
istream& operator>>(istream& st, array<T, N>& container) {
  for (auto& u : container) st >> u;
  return st;
}
template <class T>
ostream& operator<<(ostream& st, const vector<T>& container) {
  for (auto& u : container) st << u << '\n';
  return st;
}
template <class T, class U>
istream& operator>>(istream& st, pair<T, U>& p) {
  st >> p.first >> p.second;
  return st;
}
template <class T, class U>
ostream& operator<<(ostream& st, pair<T, U> p) {
  st << p.first << ' ' << p.second;
  return st;
}
template <class T, class U, class V>
pair<T, U> operator*(pair<T, U> p, V val) {
  return {p.first * val, p.second * val};
}
template <class T, class U, class V>
pair<T, U> operator/(pair<T, U> p, V val) {
  return {p.first / val, p.second / val};
}
template <class T, class U>
pair<T, U> operator-(pair<T, U> a, pair<T, U> b) {
  return {a.first - b.first, a.second - b.second};
}
template <class T, class U>
pair<T, U> operator+(pair<T, U> a, pair<T, U> b) {
  return {a.first + b.first, a.second + b.second};
}
template <class T>
T dotProduct(pair<T, T> a, pair<T, T> b) {
  return a.first * b.first + a.second * b.second;
}
template <class T>
T crossProduct(pair<T, T> a, pair<T, T> b) {
  return a.first * b.second - a.second * b.first;
}
template <class T>
T lengthPow(pair<T, T> a) {
  return a.first * a.first + a.second * a.second;
}
template <class T>
LD length(pair<T, T> a) {
  return sqrt(lengthPow(a));
}
const int N = 1e5 + 7, inf = 1e9 + 7, MOD = 114962203;
const long long INF = 1e18 + 7;
const int M = 1 << 17;
const long double PI = acos(-1);
const LD eps = 1e-4;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  cout << fixed << setprecision(15);
  int n;
  cin >> n;
  vector<pair<int, pair<int, int> > > tab;
  tab.reserve(n);
  for (int i = 0; i < n; ++i) {
    pair<int, int> pos;
    cin >> pos;
    tab.emplace_back(i + 1, pos);
  }
  sort(begin((tab)), end((tab)),
       [](pair<int, pair<int, int> > a, pair<int, pair<int, int> > b) {
         const auto [xA, yA] = a.second;
         const auto [xB, yB] = b.second;
         if (xB / 1000 == xA / 1000) {
           if (yA == yB) {
             return xA < xB;
           }
           if ((xB / 1000) & 1) {
             return yA < yB;
           } else {
             return yA > yB;
           }
         }
         return xA < xB;
       });
  for (auto u : tab) cout << u.first << ' ';
  return 0;
}

### Prompt

Please provide a cpp coded solution to the problem described below:

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;
using LD = long double;
using PLL = pair<long long, long long>;
template <class T>
bool power_2(T v) {
  static_assert(std::is_integral<T>::value, "type should be integral");
  return v && !(v & (v - 1));
}
template <class T>
istream& operator>>(istream& st, vector<T>& container) {
  for (auto& u : container) st >> u;
  return st;
}
template <class T, size_t N>
istream& operator>>(istream& st, array<T, N>& container) {
  for (auto& u : container) st >> u;
  return st;
}
template <class T>
ostream& operator<<(ostream& st, const vector<T>& container) {
  for (auto& u : container) st << u << '\n';
  return st;
}
template <class T, class U>
istream& operator>>(istream& st, pair<T, U>& p) {
  st >> p.first >> p.second;
  return st;
}
template <class T, class U>
ostream& operator<<(ostream& st, pair<T, U> p) {
  st << p.first << ' ' << p.second;
  return st;
}
template <class T, class U, class V>
pair<T, U> operator*(pair<T, U> p, V val) {
  return {p.first * val, p.second * val};
}
template <class T, class U, class V>
pair<T, U> operator/(pair<T, U> p, V val) {
  return {p.first / val, p.second / val};
}
template <class T, class U>
pair<T, U> operator-(pair<T, U> a, pair<T, U> b) {
  return {a.first - b.first, a.second - b.second};
}
template <class T, class U>
pair<T, U> operator+(pair<T, U> a, pair<T, U> b) {
  return {a.first + b.first, a.second + b.second};
}
template <class T>
T dotProduct(pair<T, T> a, pair<T, T> b) {
  return a.first * b.first + a.second * b.second;
}
template <class T>
T crossProduct(pair<T, T> a, pair<T, T> b) {
  return a.first * b.second - a.second * b.first;
}
template <class T>
T lengthPow(pair<T, T> a) {
  return a.first * a.first + a.second * a.second;
}
template <class T>
LD length(pair<T, T> a) {
  return sqrt(lengthPow(a));
}
const int N = 1e5 + 7, inf = 1e9 + 7, MOD = 114962203;
const long long INF = 1e18 + 7;
const int M = 1 << 17;
const long double PI = acos(-1);
const LD eps = 1e-4;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  cout << fixed << setprecision(15);
  int n;
  cin >> n;
  vector<pair<int, pair<int, int> > > tab;
  tab.reserve(n);
  for (int i = 0; i < n; ++i) {
    pair<int, int> pos;
    cin >> pos;
    tab.emplace_back(i + 1, pos);
  }
  sort(begin((tab)), end((tab)),
       [](pair<int, pair<int, int> > a, pair<int, pair<int, int> > b) {
         const auto [xA, yA] = a.second;
         const auto [xB, yB] = b.second;
         if (xB / 1000 == xA / 1000) {
           if (yA == yB) {
             return xA < xB;
           }
           if ((xB / 1000) & 1) {
             return yA < yB;
           } else {
             return yA > yB;
           }
         }
         return xA < xB;
       });
  for (auto u : tab) cout << u.first << ' ';
  return 0;
}

```