class Obstacles{
  ArrayList<Obstacle> obs;
  
  //constructor
  Obstacles(){
    obs=new ArrayList<Obstacle>();
  }
  
  //add obstacle
  void add(Obstacle o){
    obs.add(o);
  }
  
  //check intersection
  boolean isIntersecting(Dot dot){
    for(int i=0; i<obs.size(); i++){
      if(obs.get(i).isIntersecting(dot)){
        return true;
      }
    }
    return false;
  }
  
  //display all
  void display(){
    for(int i=0; i<obs.size(); i++){
      obs.get(i).display();
    }
  }
}