interface Pet{             
    public void buy(Animal animal); 
    public void Feed(Animal animal);
}
class Buy implements Pet  
{ 
	public void buy(Animal animal) 
    { 
      System.out.println("buy"+animal.getName()); 
    }

	@Override
	public void Feed(Animal animal) {
		// TODO Auto-generated method stub
		
	} 
}
class Feed implements Pet  
{ 
	public void Feed(Animal animal) 
    { 
      System.out.println("buy"+animal.getName()); 
    }

	@Override
	public void buy(Animal animal) {
		// TODO Auto-generated method stub
		
	} 
}
abstract class Animal  
{ 
    protected String name; 
    public String getName() { 
      return name; 
    } 
    public void setName(String name) { 
      this.name = name; 
    } 
}
class Cat extends Animal 
{ 
   public Cat(String name) {  
      this.name = name; 
    } 
}

class Boss 
{  
    public static void sell(Pet pet, Animal animal)  
    { 
      pet.buy(animal); 
    } 
}
public class PetStore  
{ 
    public static void main(String[] args) {    
      Boss boss=new Boss(); 
      Pet pet=new Buy();     
      Animal animal=new Cat("mao"); 
      Boss.sell(pet,animal);  
 
    } 
}