#include <bits/stdc++.h>   using namespace std;   char a[102];   char b[102];   char c[102];   int main() {     gets(a);     gets(b);     int l = strlen(a);     int i;     for (i = l - 1; i >= 0; i--) {       if (a[i] ==  z ) {         a[i] =  a ;       } else {         a[i] = a[i] + 1;         break;       }     }     if (!strcmp(a, b))       cout <<  No such string ;     else       cout << a;     return 0;   }   