func_code_string: #include <bits/stdc++.h>   using namespace std;   const int M = 2e5;   int infty = 1e9;   int p[M], t[M];   int main() {     int n, d, h;     cin >> n >> d >> h;     if (2 * h < d || (n > 2 && d == 1)) {       cout << -1 <<   n ;     } else {       int h1 = h, h2 = d - h, cur = 2;       for (int i = 0; i < h; i++) {         cout << cur - 1 <<     << cur <<   n ;         cur++;       }       if (d == h) {         for (int i = cur; i <= n; i++) {           cout << 2 <<     << i <<   n ;         }       } else {         if (h2 > 0) {           cout <<  1   << cur <<   n ;           cur++;         }         for (int i = 1; i < h2; i++) {           cout << cur - 1 <<     << cur <<   n ;           cur++;         }         for (int i = cur; i <= n; i++) {           cout << 1 <<     << i <<   n ;         }       }     }     return 0;   }   