.
                                 P
                        u     u m      u
                      m      p k        m
                     p         i n           p
                     k           s             k
                    i           P  u            i
                    n        m    p          n
                     s         k    i           s
                      P        n  s           P
                       u         P           u
                         m      u       m
                           p     m     p
                                   P
                                   k
                                   i
                                   n