func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     cin.tie(0);     ios_base::sync_with_stdio(0);     string x, y;     cin >> x >> y;     char ans[200];     for (int i = 0; i < x.size(); i++) {       if (y[i] == x[i]) {         ans[i] = x[i];       } else if (y[i] < x[i]) {         ans[i] = y[i];       } else {         cout << -1 <<   n ;         return 0;       }     }     for (int i = 0; i < x.size(); i++) {       cout << ans[i];     }   }   