func_code_string: #include <bits/stdc++.h>   using namespace std;   void fast() {     ios_base::sync_with_stdio(0);     cin.tie(NULL), cout.tie(NULL);   }   int gcd(int a, int b) { return b == 0 ? a : gcd(b, a % b); }   int lcm(int a, int b) { return a * (b / gcd(a, b)); }   char maze[1001][1001];   int main() {     fast();     int num, one = 0, two = 0, there = 0, six = 0, fou = 0;     cin >> num;     ;     for (int i = 0; i < num; i++) {       int x;       cin >> x;       one += bool(x == 1);       two += bool(x == 2);       there += bool(x == 3);       fou += bool(x == 4);       six += bool(x == 6);     }     if ((fou + six) != num / 3 || (one) != num / 3 || (two + there) != num / 3) {       cout << -1 << endl;       return 0;     }     vector<string> vs;     for (int i = 0; i < num / 3; i++) {       string s =   ;       s +=  1 ;       s +=    ;       if (there == six && six && there) {         s +=  3 , s +=    , s +=  6 ;         six--, there--;       } else if (two) {         s +=  2 ;         s +=    ;         if (fou)           s +=  4 , fou--;         else if (six)           s +=  6 , six--;         else {           cout << -1 << endl;           return 0;         }         two--;       } else {         cout << -1 << endl;         return 0;       }       vs.push_back(s);     }     for (int i = 0; i < vs.size(); i++) {       cout << vs[i] << endl;     }     return 0;   }   