.
                          
                                    ­  L
                             e     e   m      e
                          m       o   n         m
                        o             L               o
                       n              e                 n
                      L               m                 L
                      e                o                  e
   ­                   m           n     L             m
                      o            e      m            o
      ­                 n           o      n            n
                        L           L    e             L
                          e            m             e
                             m        o          m
                                 o      n       o
                                      n     n