text: #ifndef GAME_UTIL_H
  #define GAME_UTIL_H
  #include <map>
  #include <string>
  using namespace std;
  
  class GameUtil {
    map<string, string> opponent_pairs_;
  
   public:
    string GetEnemy(const string& me) {
      auto itr = opponent_pairs_.find(me);
      if (itr == = opponent_pairs_.end()) {
        return "";
      }
      return *itr;
    }
  };
  
  #endif