#include <bits/stdc++.h>
using namespace std;
int main() {
  int x, n;
  vector<pair<int, pair<int, int> > > team;
  int ans[805]{0};
  cin >> n;
  for (int i = 2; i <= 2 * n; i++) {
    for (int j = 1; j < 2 * n; j++)
      if (j < i) {
        cin >> x;
        team.push_back(make_pair(x, make_pair(i, j)));
      }
  }
  sort(team.rbegin(), team.rend());
  for (int i = 0; i < team.size(); i++) {
    if (ans[team[i].second.first] == 0 && ans[team[i].second.second] == 0) {
      ans[team[i].second.first] = team[i].second.second;
      ans[team[i].second.second] = team[i].second.first;
    }
  }
  for (int i = 1; i <= 2 * n; i++) cout << ans[i] << " ";
}
