3.
   +--------------------------------------------------------------------+
                        
   .  
                                    
   +--------+--------------+------------+-----------+---------+---------
                                                                  
                                                                                                                                                 
                                                                  
                                                                  
                                                                  
                                                                  
                                                                  
                                                                  
                                                                  
                                                                  
                                                                  
   +--------------------------------------------------------------------+