func_code_string: #include <bits/stdc++.h>   using namespace std;   int squ(vector<long long> &v) {     for (int i = 0; i + 3 < v.size(); i++) {       if (v[i] == v[i + 1] && v[i] == v[i + 2] && v[i] == v[i + 3]) return v[i];     }     return -1;   }   vector<long long> pa(vector<long long> &v) {     vector<long long> q;     for (int i = 0; i + 1 < v.size(); i++) {       if (i == 0 || v[i - 1] != v[i]) {         if (v[i] == v[i + 1]) q.push_back(v[i]);       }     }     return q;   }   bool checkv(pair<long long, long long> a, pair<long long, long long> b) {     if ((a.first + a.second) * (a.first + a.second) * b.first * b.second >         (b.first + b.second) * (b.first + b.second) * a.first * a.second)       return true;     return false;   }   int main() {     ios_base::sync_with_stdio(0);     int T;     cin >> T;     while (T--) {       long long n;       cin >> n;       vector<long long> v;       for (int i = 0; i < n; i++) {         long long a;         cin >> a;         v.push_back(a);       }       sort(v.begin(), v.end());       long long res = squ(v);       if (res > 0) {         for (int i = 0; i < 4; i++) cout << res <<    ;         cout <<   n ;         continue;       }       vector<long long> u = pa(v);       pair<long long, long long> cur = {u[0], u[1]};       for (int i = 0; i + 1 < u.size(); i++) {         if (checkv(cur, {u[i], u[i + 1]})) {           cur = {u[i], u[i + 1]};         }       }       cout << cur.first <<     << cur.first <<     << cur.second <<                << cur.second <<   n ;     }     return 0;   }   