class List
{
   int  value;
   List next;

   public List(int x)
   {
      value = x;
   }
}


public class Insert
{
   public static List insert( List head, List e )
   {
      List helpSol;

      /* --------------------------------------------
	  Base case: insert at the tail of an empty
         -------------------------------------------- */
      if ( head == null )
      {
         e.next = null;     // Mark e as the last list elem
	 return(e);         // e is the first list elem !
      }
      else
      {
         /* ===========================================================
            Solve the problem USING the solution of a smaller problem
	    =========================================================== */

         helpSol = insert( head.next, e ); // Have "someone else" solve
                                           // this smaller problem

         head.next = helpSol;     // Find MY solution using helpSol
         return head;             // Return MY solution
      }
   }

   public static void print(List h)
   {
      while ( h != null )
      {
         System.out.print(h.value + " ");
         h = h.next;
      }
   }

   public static void main(String[] args)
   {
      int[] inp = {1, 2, 3, 4, 5, 6, 7};

      List head = null;

      for ( int i = 0; i < inp.length; i++ )
      {
         System.out.print("List before inserting: " + inp[i] + ": ");
         print(head);
         System.out.println();

	 head = insert(head, new List(inp[i]) );

         System.out.print("List after  inserting: " + inp[i] + ": ");
         print(head);
         System.out.println("\n");
      }
   }
}