.
            
                                     L
                             a    a   d      a
                         d        y   b        d
                       y            u               y
                      b             g                b
                    u               L                 u
                    g               a                   g
                   L            d       y              L
                   a            b       u              a
                   d              g    L               d
                    y                a                  y
                     b               d                 b
                       u             y                u
                         g            b             g
                           L          u           L
                              a       g         a
                                 d    L     d
                                     y a y