#include <bits/stdc++.h>
using namespace std;
int t, a[801][801];
int main(int argc, char const *argv[]) {
  ios_base::sync_with_stdio(false);
  while (cin >> t) {
    int w = 2 * t;
    for (int i = 2; i <= w; ++i)
      for (int j = 1; j < i; ++j) {
        cin >> a[i][j];
        a[j][i] = a[i][j];
      }
    for (int k = 0; k < t; ++k) {
      int x = 2, y = 1;
      for (int i = 2; i <= w; ++i)
        for (int j = 1; j < i; ++j)
          if (a[i][j] > a[x][y]) {
            x = i;
            y = j;
          }
      for (int i = 1; i <= w; ++i) a[i][y] = a[x][i] = a[y][i] = a[i][x] = 0;
      a[x][y] = a[y][x] = -1;
    }
    for (int i = 1; i <= w; ++i)
      for (int j = 1; j <= w; ++j)
        if (a[i][j]) cout << j << ' ';
    cout << endl;
  }
  return 0;
}
