.
                                      
                        ­               Q
                              u      u   i       u
                          i           c   h           i
                       c               e                c      
                      h               Q                 h
                     e                 u                  e
                    Q            i         c              Q
                     u           h        e              u
                      i             Q     u              i
                        c               i                c
                         ­ h            c             h
                               e        h       e
                                         e