#include <bits/stdc++.h>
using namespace std;
int used[10001];
int main() {
  int n, i, j;
  cin >> n;
  int a[2 * n + 1][2 * n + 1], x, y;
  int b[n + 1];
  for (i = 2; i <= 2 * n; i++) {
    for (j = 1; j <= i - 1; j++) {
      cin >> a[i][j];
    }
  }
  for (int l = 1; l <= n; l++) {
    int mx = -101;
    x = y = 0;
    for (i = 1; i <= 2 * n; i++) {
      for (j = 1; j <= i - 1; j++) {
        if (mx < a[i][j] && used[i] == 0 && used[j] == 0) {
          mx = a[i][j];
          x = i;
          y = j;
        }
      }
    }
    b[x] = y;
    b[y] = x;
    used[x] = used[y] = 1;
    a[x][y] = -100;
  }
  for (i = 1; i <= 2 * n; i++) cout << b[i] << " ";
}
