.

                                     C
                          o       o   n      o
                        n         u   n         n
                     u              d                u
                    n                r                  n
                  d                  u                   d
                  r                  m                    r
                  u               C      o                u
                   m            n       u              m
                    C              n     d               C
                      o                r                  o
                        n             u                n
                          u           m            u
                              n       C        n
                                        o
                                        n
                                        u
                                        n
                                        d
                                        r
                                        u
                                        m