text: // graph.h
  
  #pragma once
  
  #include <iostream>
  #include <unordered_map>
  #include <unordered_set>
  
  // Type Definitions
  
  typedef std::unordered_map<int, std::unordered_set<int>> Graph;
  
  // Function Prototypes
  
  bool	read_graph(Graph &graph, std::istream &stream);
  bool	is_bicolorable(Graph &graph);
  