public class Rettangolo implements Poligono
{
   private int a;
   private int b;

   public Rettangolo(int p, int q)
   {
      a = p;
      b = q;
   }
   
   public int perimetro() { return 2 * (a + b); }
   
   public double area()
   {
      return a * b;
   }

   public int compareTo(Object obj)
   {
      Poligono p = (Poligono) obj;
      if ( area() - p.area() < 0)
         return -1;
      else if ( area() - p.area() > 0)
         return +1;
      else return 0;
   }
   
   public String toString()
   {
      return "<R>: " + a + ", " + b;
   }
}