.
                                      A
                       ­         n   n g  n
                              g      e l     g
                             e      A n      e
                            l         g e         l
                          A           l            A
                         n            A             n
                        g             n               g
                       e               g                e
                      l                e l                 l
                     A              A  n                A
                     n             g     e               n
                     g              l     A               g
                      e              n  g               e
                        l               e                l
                          A            l              A
                              n        A          n
                                   g    n      g
                                      el g le
                                          e
                                          l