import java.net.InetAddress;
import java.net.UnknownHostException;

public class IPtoDNS
   {
   /**
    * Find the DNS name associated with an IP
    *
    * @param args not used
    */
   public static void main ( String[] args )
      {
      try
         {
         InetAddress[] addresses = InetAddress.getAllByName( "24.69.120.20" /* ip or DNS name */ );

         for ( int i=0; i<addresses.length; i++ )
            {
            String hostname = addresses[i].getHostName();
            out.println( hostname );
            }
         }
      catch ( UnknownHostException e )
         {
         out.println( "unknown host" );
         }

      }
   }