.

                                   H
                          o      o p       o
                       p         e H          p
                      e            o               e
                     H          p    e           H
                     o          H    o            o
                      p          p    e            p
                       e          H  o            e
                        H           p            H
                          o          e            o
                             p      H         p
                                e     o      e
                                       P
                                       e