.
                              football
                        ­   footballfoot
                          ball  football
           ­                footballfoot
                           f o o t b a l l
                           f o o t b a l l
                           f o o t b a l l
                           f o o t b a l l
                           f o o t b a l l
                           f o o t b a l l
                           f o o t b a l l
                           f o o t b a l l
                           f o o t b a l l
                           f o o t b a l l
                        footballfootball
                      ­football    football
                       football  football