public class Snake extends Reptile{
  private final static int NUM_LEGS = 0; // all snakes have 0 legs
  private final int poison_level;  // 0 -> 10, once set cannot change
  
  public Snake(String name, int age, int weight, 
               boolean poisonous, int poison_level){
    super(name, age, weight, poisonous, NUM_LEGS);
    this.poison_level = poison_level;
    
  }
  
  public int compareTo(Object o){
    try{
      if(this.poison_level == ((Snake)o).poison_level)
        return 0;
      else if(this.poison_level > ((Snake)o).poison_level)
        return 1;
      else 
        return -1;
    }catch(Exception e){
      //if the comparison fails, then we 
      //assume both are not Snakes and 
      //must be compared in the superclass Reptile
      return super.compareTo(o); 
    }
  }
  
  
  
}