1                                  16                                                    7              

                            20                               8                                                          

                                                                                    22                                   

                     9                                 15                                              10              

                                        2                                                                             23

        17                                                                              18                              

                             3                                     12                                                    

                                                       24                                                     4          

                     11                                                                   13                             

                                        5                                                                    6            

    19                                      21                                 14