.
                             P   Pig    P
                          i       Pig        i
                       g         Pig           g
                      P          Pig             P
                     i              P                i
                     g            i   g             g
                     P           P    i             P
                      i            g   P            i
                        g          i   g          g
                          P         Pi         P
                              i       g      i
                                  g  ×   g