#include <bits/stdc++.h>
using namespace std;
const int inf = 1000000007;
const long long linf = 1LL << 62;
const unsigned long long ulinf = 1ULL << 63;
const double eps = 0.000001;
const double pi = 3.14159265358979323846;
template <class T>
T abs(T a) {
  return a >= 0 ? a : -a;
}
template <class T>
T sqr(T a) {
  return a * a;
}
template <class T>
T gcd(T a, T b) {
  return b ? gcd(b, a % b) : a;
}
template <class T>
T mod(T a, T b) {
  return (a % b + b) % b;
}
long long powmod(long long a, long long b, long long c) {
  if (b == 0) return 1;
  long long ret = powmod(a, b >> 1, c);
  ret = ret * ret % c;
  if (b & 1) ret = ret * a % c;
  return ret;
}
template <class T>
void maxe(T &a, T b) {
  if (a < b) a = b;
}
template <class T>
void mine(T &a, T b) {
  if (a > b) a = b;
}
int iszero(double a) { return abs(a) <= eps; }
template <class T>
void geti(T &a) {
  a = 0;
  T b = 1;
  char c = getchar();
  if (c == '-')
    b = -1;
  else
    a = c - 48;
  while ((c = getchar()) != ' ' && c != '\n') a = a * 10 + c - 48;
  a *= b;
}
void fileio_in_out() {
  freopen(".in", "r", stdin);
  freopen(".out", "w", stdout);
}
void fileio_txt() {
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
}
const int N = 111111;
const int M = 111111;
int test;
int n, m, k, ans;
int a[N];
int getans() {
  if (a[5] || a[7]) return 0;
  if (a[1] != a[2] + a[3]) return 0;
  if (a[2] + a[3] != a[4] + a[6]) return 0;
  if (a[4] > a[2] || a[6] < a[3]) return 0;
  return 1;
}
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) {
    scanf("%d", &m);
    a[m]++;
  }
  ans = getans();
  if (ans) {
    for (int i = 1; i <= a[4]; i++) puts("1 2 4");
    for (int i = 1; i <= a[6] - a[3]; i++) puts("1 2 6");
    for (int i = 1; i <= a[3]; i++) puts("1 3 6");
  } else
    puts("-1");
  return 0;
}
