#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  n *= 2;
  map<int, pair<int, int> > strength_map;
  for (int i = 1; i < n; i++) {
    for (int j = 0; j < i; j++) {
      int val;
      cin >> val;
      strength_map[val] = {i, j};
    }
  }
  int ans[802];
  for (int i = 0; i < 802; i++) ans[i] = -1;
  int count = 0;
  for (auto itr = strength_map.rbegin(); itr != strength_map.rend(); itr++) {
    int i = (itr->second).first;
    int j = (itr->second).second;
    if (ans[i] == -1 && ans[j] == -1) {
      ans[i] = j;
      ans[j] = i;
    }
  }
  for (int i = 0; i < n; i++) {
    cout << ans[i] + 1 << " ";
  }
  cout << endl;
  return 0;
}
