12   7                    

                    

                 28 

                     

                   

                  

                  

   

                       

                 

                  

                  

                         

                 

                   

                   

                  

                     

                 

                   

                        

                   

                

               

                  

                     

                 

                    

                    

                   

                 

                  

               

                

      

                     

                   

                  

   