.
                                    Zi
                             i      pp       i
                          p        er          p
                         p         zi             p
                        e        p     p          e
                        r        e       r          r
                        z        z       i           z
                        i          p    p           i
                          p        e  r           p
                           p         z           p
                              e       i         e
                                 r    p     r
                                       i
                                       t