using System;
using System.Collections;

class App{

 public static void Main(){
   IntSet s1 = new IntSet(),
          s2 = new IntSet();

   s1.Insert(1); s1.Insert(2);  s1.Insert(3);
   s1.Insert(4); s1.Insert(5);  s1.Insert(6);
   s1.Insert(5); s1.Insert(6);  s1.Insert(8);
   s1.Delete(3); s1.Delete(6);  s1.Insert(9);

   s2.Insert(8); s2.Insert(9); 

   Console.WriteLine("s1: {0}", s1);
   Console.WriteLine("s2: {0}", s2);

// Exercises:
// Console.WriteLine("{0}", s2.Intersection(s1));
// Console.WriteLine("{0}", s2.Union(s1));
// Console.WriteLine("{0}", s2.Diff(s1));

   if (s1.Subset(s2))
     Console.WriteLine("s1 is a subset of s2");
   else 
     Console.WriteLine("s1 is not a subset of s2");

   if (s2.Subset(s1))
     Console.WriteLine("s2 is a subset of s1");
   else 
     Console.WriteLine("s2 is not a subset of s1");
 }
}