    
                                                                          
                                                                                                                                                                      
        12                                                                                                                                           
                                      
                         12   5   60                                     12                  12               24                                                                                                                                                                                                                                                                                                                                        20  25  37                                                                                                         
                           7      5                 7              5                                                                                                           
                                                          