.
                                       M
                              a      au        a
                           u         dA          u
                          d            d             d
                         A          a   m          A
                         d          s     M          d
                         a          a      u           a
                         m         d     A          m
                           s          d   m          s
                            M           s           M
                              a          M         a
                                 u       a        u
                                    d    u     d
                                          d