.

                                          C
                                a       a t       a
                              t          Ca           t
                            C            t              C
                            a          C  a            a
                             t          t   C            t
                             C         C  a           C
                               a        t  C          a
                                 t        a t        t
                                   C      C      C
                                            A
                                            T