#include <bits/stdc++.h>
using namespace std;
int n, a[1000][1000], ans[1000];
bool used[1000];
int main() {
  cin >> n;
  for (int i = 1; i < 2 * n; ++i) {
    a[i][i] = -1000000000;
    for (int j = 0; j < i; ++j) {
      cin >> a[i + 1][j + 1];
      a[j + 1][i + 1] = a[i + 1][j + 1];
    }
  }
  for (int i = 0; i < 2 * n + 1; ++i) used[i] = false;
  for (int k = 0; k < n; ++k) {
    int maxa = -1000000000, max1, max2;
    for (int i = 1; i < 2 * n + 1; ++i) {
      for (int j = 1; j < 2 * n + 1; ++j) {
        if (!used[i] && !used[j] && a[i][j] > maxa) {
          maxa = a[i][j];
          max1 = i;
          max2 = j;
        }
      }
    }
    ans[max1] = max2;
    ans[max2] = max1;
    used[max1] = true;
    used[max2] = true;
  }
  for (int i = 1; i < 2 * n + 1; ++i) cout << ans[i] << ' ';
  return 0;
}
