#include <bits/stdc++.h>
using namespace std;
long long A[300001];
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(nullptr);
  long long n;
  cin >> n;
  if (n % 2) {
    for (int i = 1; i <= n; i++) {
      if (i % 2 == 0) cout << i << " ";
    }
    for (int i = n; i >= 1; i--) {
      if (i % 2 == 0) cout << i << " ";
    }
    for (int i = 1; i <= n - 1; i++) {
      if (i % 2) cout << i << " ";
    }
    cout << n << " ";
    for (int i = n - 1; i >= 1; i--) {
      if (i % 2) cout << i << " ";
    }
    cout << n << endl;
  } else {
    for (int i = 1; i <= n; i++)
      if (i % 2) cout << i << " ";
    for (int i = n; i >= 1; i--)
      if (i % 2) cout << i << " ";
    for (int i = 1; i <= n - 1; i++) {
      if (i % 2 == 0) cout << i << " ";
    }
    cout << n << " ";
    for (int i = n - 1; i >= 1; i--) {
      if (i % 2 == 0) cout << i << " ";
    }
    cout << n << endl;
  }
}

### Prompt

Please create a solution in CPP to the following problem:

You have array a that contains all integers from 1 to n twice. You can arbitrary permute any numbers in a.

Let number i be in positions xi, yi (xi < yi) in the permuted array a. Let's define the value di = yi - xi — the distance between the positions of the number i. Permute the numbers in array a to minimize the value of the sum <image>.

Input

The only line contains integer n (1 ≤ n ≤ 5·105).

Output

Print 2n integers — the permuted array a that minimizes the value of the sum s.

Examples

Input

2


Output

1 1 2 2


Input

1


Output

1 1

### Response

```cpp
#include <bits/stdc++.h>
using namespace std;
long long A[300001];
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(nullptr);
  long long n;
  cin >> n;
  if (n % 2) {
    for (int i = 1; i <= n; i++) {
      if (i % 2 == 0) cout << i << " ";
    }
    for (int i = n; i >= 1; i--) {
      if (i % 2 == 0) cout << i << " ";
    }
    for (int i = 1; i <= n - 1; i++) {
      if (i % 2) cout << i << " ";
    }
    cout << n << " ";
    for (int i = n - 1; i >= 1; i--) {
      if (i % 2) cout << i << " ";
    }
    cout << n << endl;
  } else {
    for (int i = 1; i <= n; i++)
      if (i % 2) cout << i << " ";
    for (int i = n; i >= 1; i--)
      if (i % 2) cout << i << " ";
    for (int i = 1; i <= n - 1; i++) {
      if (i % 2 == 0) cout << i << " ";
    }
    cout << n << " ";
    for (int i = n - 1; i >= 1; i--) {
      if (i % 2 == 0) cout << i << " ";
    }
    cout << n << endl;
  }
}

```