AAA                                                                                                                      
                                                                                                                                        
                           Off                                                      On                                                  
                                                                                                                                        
                                                                                                                                        
               BBB                                                                                                                      
                                                                                                                                        
                                                                                                                                        
                           Off                                                                                                          
                                                                                                                                        
                                                                                                                                        
               CCC                                                                                                                      
                                                                                                                                        
                           Off                                                                                                        On
                                                                                                                                        
                                                                                                                                        
                                                                   0                                                 1