- ,
()




                    
                                                                   2.
   +-----------------------------------------------------------------------------------------------------------+
                                     
   -   ( - ( - 
               .      .   
           (-    - (-    -    
             )        )             )                )                         
   +--------+----------+-----------+-----------+--------+----------+-----------+-----------+--------+----------
                                                                                                     
                                                                                                     
                                                                                                     
                                                                                                     
                                                                                                     
                                                                                                     
                                                                                                     
                                                                                                     
                                                                                                     
                                                                                                     
                                                                                                     
                                                                                                     
                                                                                                     
                                                                                                     
   +-----------------------------------------------------------------------------------------------------------+                                                                               +