.

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