no                                                                 yes                                
                                                                                                         x?                                                                 
                                                                                                                                                                            
                                                                                                                                                                            
                                                                                                                                                                            
                                            A                                                                                                                              B
                                                                                                                                                                            
                                                                                                                                                                            
                                                                                                                                                                            
                                      y?                                 yes                                                                                                
                                                                                                                                                                            
                                                     no                                                                                                                     
                                                                                                                                                                            
                                                                                                                                                                            
                                            C                                                                                                                               
                                                                                                                                                                            
                                                                                                                                                                            
                                                                                                                                                                            
                                                                                                                                                                            
                                                                                                                                                                            
                                                                                                                                                                            
                                                                                                                                                                            
                                                                                                                                                                            
                                                                                                               D                                                            
                                                                                                                                                                            
                                                                                                                                                                            
                                                                                                                                                                            
                                                                                                                                                                            
                                                                                                                                                                            
                                                                                                                                                                            
                                                                                                                                                                            
                                                                                                                                                                            
                                                                                                               E