#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, x;
  scanf("%d", &n);
  vector<pair<int, pair<int, int>>> v;
  for (int i = 1; i < 2 * n; i++) {
    for (int j = 0; j < i; j++) {
      scanf("%d", &x);
      v.push_back(make_pair(x, make_pair(i, j)));
    }
  }
  pair<int, pair<int, int>> t = make_pair(-1, make_pair(-1, -1));
  sort((v).begin(), (v).end());
  reverse((v).begin(), (v).end());
  vector<bool> vis((int)v.size());
  vector<int> ans(2 * n);
  for (int i = 0; i < (int)v.size(); i++) {
    if (v[i] == t) continue;
    int a = v[i].second.first;
    int b = v[i].second.second;
    ans[a] = b + 1;
    ans[b] = a + 1;
    for (int j = i; j < (int)v.size(); j++) {
      if ((a == v[j].second.first || a == v[j].second.second) ||
          (b == v[j].second.first || b == v[j].second.second))
        v[j] = t;
    }
  }
  for (int i = 0; i < (int)ans.size(); i++) {
    if (i) printf(" ");
    printf("%d", ans[i]);
  }
  printf("\n");
}
