import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
public class Test
{
 public static void main(String[] args)
 {
  Set<Element> set = new HashSet<Element>();
  Element i1 = new Element(1);
  Element i2 = new Element(2);
  Element i3 = new Element(3);
  set.add(i1);
  set.add(i2);
  set.add(i3);
  System.out.println("Before changed:");
  printSet(set);
  i1.setValue(2);
  System.out.println(i1.equals(i2));
  System.out.println("After changed:");
  printSet(set);
 }
 public static void printSet(Set set)
 {
  Iterator it = set.iterator();
  while (it.hasNext())
  {
   System.out.println(it.next());
  }
 }
}
class Element
{
 private int value;
 public Element(int value)
 {
  this.value = value;
 }
 public void setValue(int value)
 {
  this.value = value;
 }
 public int getValue()
 {
  return this.value;
 }
 @Override
 public String toString()
 {
  return "" + this.value;
 }
 @Override
 public boolean equals(Object obj)
 {
  if(this ==(Element)obj)
   return true;
  if (!(obj instanceof Element))
  {
   return false;
  }
  if (((Element) obj).getValue() == this.getValue())
  {
   return true;
  }
  return false;
 }
 @Override
 public int hashCode()
 {
  return 37 + this.value;
 }
}