func_code_string: #include <bits/stdc++.h>   using namespace std;   const unsigned long long INF = 1000 * 1000 * 1000;   const double eps = 1e-9;   int main() {     string s;     cin >> s;     int pos = 0;     for (char c =  z ; c >=  a ; c--) {       int tek = pos;       for (int i = tek; i < s.size(); i++)         if (s[i] == c) {           cout << s[i];           pos = i;         }     }     return 0;   }   