func_code_string: #include <bits/stdc++.h>   using namespace std;   int main(int argc, char* argv[]) {     string s;     string t;     cin >> s >> t;     string result(s);     int carry = 1;     for (int ii = s.length() - 1; ii >= 0; --ii) {       result[ii] = (char)(s[ii] + carry);       if (result[ii] >  z ) {         result[ii] =  a ;         carry = 1;       } else {         carry = 0;       }     }     if (result == t) {       cout <<  No such string  << endl;     } else {       cout << result << endl;     }     return 0;   }   