func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n, i;     cin >> n;     if (n == 1 || n == 2)       cout <<  -1 ;     else {       for (i = n; i >= 1; i--) cout << i <<    ;       cout <<   n ;     }     return 0;   }   