// contravariance in java

class student implements Comparable<student>
{
   public final String name; // can be sorted
   public student(String n) {name=n;}
 
   public int compareTo(student other) 
   { return name.compareTo(other.name); } // compare Strings alphabetically
}

class undergrad extends student 
{
  public String major;
  public undergrad(String n, String m) {super(n); major=m;}

  // try to inherit compareTo
}

// generic sorting class
class sorter<T extends Comparable<? super T>>
{
  public void bubblesort(T[] A)
  { 
     for(int i=0;i<A.length-1;i++)
       for (int j=0;j<A.length-1-i;j++)
         if (A[j].compareTo(A[j+1])>0)	
          {  T x = A[j]; A[j]=A[j+1]; A[j+1]=x; }
  }
}//sorter

public class contraex
{
  public static void main(String[] aa)
  {
    undergrad[] A = 
      {new undergrad("shashank","cs"), new undergrad("adam","cs")};
    sorter<undergrad> S = new sorter<undergrad>();
    S.bubblesort(A);
    for (undergrad x : A) System.out.println(x.name);
  }
}