func_code_string: #include <bits/stdc++.h>   using namespace std;   void _dbg(string) { cout << endl; }   template <class H, class... T>   void _dbg(string s, H h, T... t) {     int l = s.find( , );     cout << s.substr(0, l) <<   =   << h <<  ,  ;     _dbg(s.substr(l + 1), t...);   }   template <class T, class U>   ostream& operator<<(ostream& o, const pair<T, U>& p) {     o <<  (  << p.first <<  ,  << p.second <<  ) ;     return o;   }   template <class T>   ostream& operator<<(ostream& o, const vector<T>& v) {     o <<  [ ;     for (T t : v) {       o << t <<  , ;     }     o <<  ] ;     return o;   }   const int N = 100000;   int n, m;   bool used[N + 5];   char s[N + 5];   int hoge(char c) {     int crnt = 0;     int last = -1;     int ret = 0;     for (int i = (int)(0); i < (int)(n); i++) {       crnt++;       if (s[i] == c) last = i;       if (used[i]) crnt = 0;       if (crnt == m) {         if (i - last >= m) return -1;         crnt = i - last;         used[last] = true;         ret++;       }     }     return ret;   }   int main() {     cin >> m >> s;     n = strlen(s);     for (int i = (int)(0); i < (int)(26); i++) {       char c = i +  a ;       int r = hoge(c);       if (r == -1) {         r = 0;         for (int j = (int)(0); j < (int)(n); j++)           if (s[j] == c) {             r++;             used[j] = true;           }       } else {         i = 100;       }       for (int j = (int)(0); j < (int)(r); j++) printf( %c , c);     }     cout << endl;     return 0;   }   