.
                                       M
                             a        ar        a
                          r           ch            r
                         c            M               c
                        h           a  r               h
                       M          c   h              M
                        a           M a               a
                         r            r c               r
                          c            h              c
                              h       M       h
                                        a
                                        r
                                        c
                                        h