package  Pack;

 import  java.util.HashSet;
 import  java.util.Iterator;

 class  Cat{
	 int  x;
	 public  Cat( int  i) {
		x =i;
	}

	@Override
	 public   boolean  equals(Object obj) {
		 if  (obj  instanceof  Cat){
			 if  (((Cat)obj).x ==  this .x)
				  return  true;
		}
		 return  false;
	}

	@Override
	 public   int  hashCode() {
		 return  x* 5 ;
	}
	
}

 public   class  Dog {
	 public   static   void  main(String[] args) {
		HashSet hs =  new  HashSet( 4 );

		hs.add( new  Cat( 1 ));
		hs.add( new  Cat( 2 ));
		hs.add( new  Cat( 3 ));
		Iterator it = hs.iterator();
		Cat hsСat = (Cat) it.next();
		
		hsСat.x= 10 ;
		 if  (hs.contains(hsСat)) {
			System.out.println ("Contains");
		}
	}
}