#include <bits/stdc++.h>
using namespace std;
int p[1111];
int main() {
  ios::sync_with_stdio(0);
  cin.tie(NULL);
  int n, x;
  cin >> n;
  n *= 2;
  vector<pair<int, pair<int, int> > > v;
  for (int i = 2; i <= n; ++i)
    for (int j = 1; j < i; ++j) {
      cin >> x;
      v.push_back({x, {i, j}});
    }
  sort(v.begin(), v.end());
  reverse(v.begin(), v.end());
  for (int i = 0; i < v.size(); ++i) {
    if (p[v[i].second.first] == 0 && p[v[i].second.second] == 0) {
      p[v[i].second.first] = v[i].second.second;
      p[v[i].second.second] = v[i].second.first;
    }
  }
  for (int i = 1; i <= n; ++i) cout << p[i] << " \n"[i == n];
  return 0;
}
