#include <bits/stdc++.h>
using namespace std;
int answer[8000];
struct team {
  int strength;
  int x;
  int y;
};
bool compare(const team &t1, const team &t2) {
  return (t1.strength > t2.strength);
}
vector<team> vec;
int main() {
  int n;
  cin >> n;
  for (int i = 2; i <= 2 * n; i++) {
    for (int j = 1; j < i; j++) {
      team obj;
      cin >> obj.strength;
      obj.x = i;
      obj.y = j;
      vec.push_back(obj);
    }
  }
  sort(vec.begin(), vec.end(), compare);
  int countt = 0;
  for (int k = 0; k < vec.size(); k++) {
    if ((answer[vec[k].x] == 0) && (answer[vec[k].y] == 0)) {
      answer[vec[k].x] = vec[k].y;
      answer[vec[k].y] = vec[k].x;
      countt++;
    }
    if (countt == n) break;
  }
  for (int i = 1; i <= 2 * n; i++) cout << answer[i] << " ";
  cout << endl;
  return 0;
}
