                             5                 5
                     ___..--' `-.__        _.-' `-.__
                    2,p            9      3,r        9
                   /   \          /      /   \      /
                  1     3,r      8   => 1     4    8
                           \   _'                _'
                            4 6                 6
                               \                 \
                                7                 7
 
