#include <bits/stdc++.h>
using namespace std;
template <class T>
bool umin(T& a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
bool umax(T& a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
vector<pair<int, pair<int, int> > > v;
int a, b, c, se[1009];
int main() {
  cin >> a;
  for (int i = 2; i <= 2 * a; i++)
    for (int j = 1; j < i; j++)
      cin >> b, v.push_back(make_pair(b, make_pair(i, j)));
  sort(v.begin(), v.end());
  for (int i = int(v.size() - 1); i >= 0; i--)
    if (se[v[i].second.first] == 0 && se[v[i].second.second] == 0)
      se[v[i].second.first] = v[i].second.second,
      se[v[i].second.second] = v[i].second.first;
  for (int i = 1; i <= 2 * a; i++) cout << se[i] << " ";
  return 0;
}
