.
                                     M
                             o     on      o
                           n       s t         n
                          s         er           s
                          t          M            t
                         e         o   n          e
                          r         s    t          r
                           M       e  r        M
                             o        M        o
                               n      o       n
                                 s     n     s
                                        s