func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     string s, t;     while (cin >> s >> t) {       int n = s.size();       string res;       for (int i = n - 1; i >= 0; --i) {         char& c = s[i];         ++c;         int x = 0;         if (c >  z ) {           c =  a ;           x = 1;         }         if (!x and s < t) {           res = s;           break;         }       }       cout << (res.empty() ?  No such string  : res) << endl;     }   }   