text: #include <bits/stdc++.h>
  
  using namespace std;
  
  const int Vmax = 100000 + 1;
  const int Emax = 200000 + 1;
  
  struct Graph
  {
      struct Node
      {
          int nod;
          int next;
      };
  
      Node listEdges[Emax];
      int head[Vmax];
      int contor;
  
      Graph()
      {
          contor = 0;
  
          for ( int i = 0; i < Vmax; ++i )
              head[i] = 0;
      }
  
      void addEdge( int a, int b )
      {
          contor++;
          listEdges[contor].nod = b;
          listEdges[contor].next = head[a];
          head[a] = contor;
      }
  };
  
  int main()
  {
      return 0;
  }
  