#include <bits/stdc++.h>
using namespace std;
vector<long long int> prime;
unordered_set<long long int> stprime;
void sieve(long long int n) {
  bool p[n + 1];
  memset(p, true, sizeof(p));
  for (long long int i = 2; i * i <= n; i++) {
    if (p[i]) {
      for (int j = i * i; j <= n; j += i) {
        p[j] = false;
      }
    }
  }
  for (long long int i = 2; i <= n; i++) {
    if (p[i]) {
      prime.push_back(i);
      stprime.insert(i);
    }
  }
}
void solve() {
  long long int m;
  cin >> m;
  long long int arr[8];
  memset(arr, 0, sizeof(arr));
  for (int i = 0; i < m; i++) {
    long long int a;
    cin >> a;
    arr[a]++;
  }
  m /= 3;
  if (arr[1] != m || arr[5] | arr[7] || arr[2] < arr[4] || arr[6] < arr[3] ||
      arr[2] + arr[3] != arr[4] + arr[6]) {
    cout << "-1" << endl;
  } else {
    for (int i = 1; i <= arr[4]; i++) cout << "1 2 4" << endl;
    for (int i = 1; i <= arr[2] - arr[4]; i++) cout << "1 2 6" << endl;
    for (int i = 1; i <= arr[3]; i++) cout << "1 3 6" << endl;
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long int t;
  t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
