.

                                       H
                                 a   a v    a
                               v     eH       v
                             e       a v         e
                           a          a             a
                           g        g     r          g
                           r        e     a          r
                            e        t    d         ­ e
                             a        a  y          a
                               t        H           t
                                d       a        d
                                  a     v      a
                                     y  e   y

.
                                    F
                             a    ac     a
                           c      eb       c
                          e       oo        e
                         b         k          b
                         o      F    a       o
                          o     c     e       o
                          k      b   o       k
                           F      o  k      F
                             a      F      a
                               c    a     c
                                 e  c  e
                                     e

.
                                    Z
                              o   oo    o
                            o     Zo       o
                          Z       oZ         Z
                         o         o            o
                         o       o    Z        o
                          Z      o     o        Z
                          o      Z     o       o
                           o      o   Z       o
                             Z     o o      Z
                                o    Z     o
                                  o  o  o
                                       o

.
                                        b
                     ­            a    a d     a
                               d      b a       d
                              b        d            b
          ­                   a        b  a          a
                              d       d   b         d
                              b       a   d         b
                               a       b  a         a
                                d        d         d
                                  b      b        b
           ­                          a    a     a
                                           d

.
                                    
                                 rose  rose
                              rose rose ros
                             e  rose  rose  ro
                              rose rose rose
                              rose rose rose
                              rose rose rose
                              rose rose rose
                              rose rose rose
                              rose rose rose
                              rose rose rose
                              rose rose rose
                              rose rose rose
                              rose rose rose
                              rose rose rose
                              rose rose rose
                              rose rose rose
               rose rose                 rose rose
           rose rose rose         rose rose rose
         rose rose rose  r      ose rose rose  ro
          se rose rose  r           ose rose rose
              rose rose                   rose rose

.
                                      V
                       ­           i  io   i
                               o    le      o
                              l       t         l
                            e      V  i        e
                           t        o   l         t
                          V       e     t        V
                           i        V   i         i
                            o       o  l         o
                              l        e         l
                                e      t       e
                                   t    •    t

.
                                       B
                                u     ut      u
                              t        te          t
                             t          r             t
                            e        c   u           e
                            r        p    B          r
                             c        u   t           c
                             u         t  e          u
                               p         r           p
                                B        c         B
                                  u      u       u
                                     t     p     t
                                        t      t