l20.c    -   l18.c
        | \polana.c/
     l16.c /  -   \l19.c
        |            |
      l14.c-l15.c-l16.c
        \  /  |    |
      l13.c-l12.c-l11.c
                   /
               l10.c  l09.c
                    \/
                    l08.c  
                        \
                        l07.c
                         |
	                l06.c
                         |
                        l05.c-l03.c
                                 \
                               l02.c    
                                 |
                                l01.c