#include <cstdio>
 #include <cstdlib>
 #include <cstring>
 #include <algorithm>
 using namespace std;
 ];
 int main(void) {
 #ifndef ONLINE_JUDGE
     freopen("in.txt", "r", stdin);
 #endif
     int n, i, j, tmp;
     bool flag;
     while (~scanf("%d", &n))  {
         flag = true;
         memset(cnt, , sizeof(cnt));
         ; i < n; ++i) {
             scanf("%d", &tmp);
             cnt[tmp]++;
         }
         ] + cnt[];
         ) {
             printf("-1\n"); continue;
         }
         , c126 = , c124 = ;
         ] >= cnt[] && cnt[] >= cnt[])
         {cnt[] -= cnt[]; cnt[] -= cnt[]; c136 = cnt[];}
         else flag = false;
         ] >= cnt[] && cnt[] >= cnt[])
         {cnt[] -= cnt[]; cnt[] -= cnt[]; c126 = cnt[];}
         else flag = false;
         ] >= cnt[] && cnt[] >= cnt[]) {
         c124 = cnt[]; cnt[] -= cnt[]; cnt[] -= cnt[];}
         else flag = false;
         ]+cnt[] > ) flag = false;
         if (flag) {
             ; i < c136; ++i) printf("1 3 6\n");
             ; j < c126; ++j) printf("1 2 6\n");
             ; i < c124; ++i) printf("1 2 4\n");
         }
         else printf("-1\n");
     }
     ;
 }