func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int t;     cin >> t;     while (t--) {       int n, k;       cin >> n >> k;       string s;       cin >> s;       sort(s.begin(), s.end());       map<char, int> store;       for (int i = 0; i < n; i++) {         store[s[i]]++;       }       if (store.size() == 1) {         int temp = n / k;         if (n % k != 0) temp++;         for (int i = 0; i < temp; i++) cout << s[0];       } else if (store.size() == 2 && store[s[0]] == k) {         cout << s[0];         int temp = n / k;         if (n % k != 0) temp++;         for (int i = 0; i < temp - 1; i++) cout << s[k];       } else {         if (s[0] != s[k - 1])           cout << s[k - 1];         else {           for (int i = k - 1; i < n; i++) cout << s[i];         }       }       cout <<   n ;     }     return 0;   }   