func_code_string: #include <bits/stdc++.h>   using namespace std;   template <typename Arg1>   void __f(const char* name, Arg1&& arg1) {     cerr << name <<   :   << arg1 << std::endl;   }   template <typename Arg1, typename... Args>   void __f(const char* names, Arg1&& arg1, Args&&... args) {     const char* comma = strchr(names + 1,  , );     cerr.write(names, comma - names) <<   :   << arg1 <<   |  ;     __f(comma + 1, args...);   }   int main(void) {     int n;     scanf( %d , &n);     int d;     scanf( %d , &d);     int h;     scanf( %d , &h);     if (d > 2 * h || d < h || (n > 2 && (d <= 1)) || (h < 1)) {       cout <<  -1 n ;       return 0;     } else {       int it = 1;       int c = 0;       while (it <= h) {         cout << it <<     << it + 1 << endl;         it++;         c++;       }       if (d != h) {         if (c < n - 1) {           cout << 1 <<     << it + 1 << endl;           c++;           it += 1;           d = d - h - 1;           while (d > 0 && c < n - 1) {             cout << it <<     << it + 1 << endl;             it++;             d--;             c++;           }           while (c < n - 1) {             cout << 1 <<     << it + 1 << endl;             it++;             c++;           }         }       } else {         if (c < n - 1) {           cout << 2 <<     << it + 1 << endl;           c++;           it += 1;           d = d - h - 1;           while (d > 0 && c < n - 1) {             cout << it <<     << it + 1 << endl;             it++;             d--;             c++;           }           while (c < n - 1) {             cout << 2 <<     << it + 1 << endl;             it++;             c++;           }         }       }     }     return (0);   }   