#include <bits/stdc++.h>
using namespace std;
const int MOD = 1000000007;
double PI = 4 * atan(1);
int n, team[801];
vector<pair<int, pair<int, int>>> a;
int main() {
  cin >> n;
  for (int i = 2; i < 2 * n + 1; i++)
    for (int j = 1; j < i; j++) {
      pair<int, pair<int, int>> b;
      scanf("%d", &b.first);
      b.second.first = i, b.second.second = j;
      a.push_back(b);
    }
  sort(a.begin(), a.end());
  for (int i = a.size() - 1; i >= 0; --i) {
    if (team[a[i].second.first] == 0 && team[a[i].second.second] == 0) {
      team[a[i].second.first] = a[i].second.second;
      team[a[i].second.second] = a[i].second.first;
    }
  }
  for (int i = 1; i < 2 * n + 1; i++) cout << team[i] << " ";
}
