#include <bits/stdc++.h>
using namespace std;
int n;
vector<int> a;
void Solve() {
  cin >> n;
  a.resize(2 * n, -1);
  for (int i = 1; i < n; i++) {
    auto beg = 0;
    if (i % 2 == 1)
      beg = i / 2;
    else
      beg = n + i / 2 - 1;
    auto end = n - i + beg;
    a[beg] = i;
    a[end] = i;
  }
  for (int i = 0; i < a.size(); i++)
    if (a[i] == -1) a[i] = n;
  for (int i = 0; i < 2 * n; i++) cout << a[i] << " ";
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  Solve();
}
