func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     string s =   ;     cin >> s;     int y = 0;     while (s[y] ==  a  && y <= s.length()) ++y;     for (int i = y; i < s.length(); ++i) {       if (s[i] ==  a )         break;       else         --s[i];     }     if (y == s.length()) s[s.length() - 1] =  z ;     cout << s << endl;   }   