#include <bits/stdc++.h>
using namespace std;
int a[808][808];
int b[808];
int main() {
  int n, i, j;
  while (~scanf("%d", &n)) {
    for (i = 2; i <= 2 * n; i++) {
      for (j = 1; j <= i - 1; j++) {
        scanf("%d", &a[i][j]);
      }
    }
    int k, x, y;
    for (k = 1; k <= n; k++) {
      int maxn = 0;
      for (i = 2; i <= 2 * n; i++) {
        for (j = 1; j <= i - 1; j++) {
          if (maxn < a[i][j]) {
            maxn = a[i][j];
            x = i;
            y = j;
          }
        }
      }
      b[x] = y;
      b[y] = x;
      for (i = 1; i <= 2 * n; i++) {
        a[i][x] = 0;
        a[x][i] = 0;
        a[i][y] = 0;
        a[y][i] = 0;
      }
    }
    for (i = 1; i < 2 * n; i++) {
      printf("%d ", b[i]);
    }
    printf("%d\n", b[2 * n]);
  }
  return 0;
}
