.
                            
                                     V
                              a    a  g     a
                          g        i  n         g
                        i             a              i
                       n             V               n
                      a               a                a
                     V                g                 V
                     a             i        n            a
                      g            a       V            g
                        i            a     g            i
                          n           i  n           n
                              a         a         a
                                         V
                                         a
                                         g
                                         i