[(0,1),(0,2),(2,3),(1,3),(2,4),(3,4),(4,5),(5,6),(6,7),(1,7),(7,8),(8,9),(6,10),(8,11),(11,12),(9,13),(13,14),(10,14),(14,15),(12,15),(10,16),(12,17),(17,18),(5,19),(18,20),(11,21),(18,22),(17,23),(9,24),(13,25),(16,26),(15,27),(16,28)]
[(0,1),(1,2),(0,2),(1,3),(2,4),(3,5),(4,5),(4,6),(6,7),(7,8),(5,9),(7,9),(8,10),(3,11),(9,12),(6,13),(12,14),(14,15),(15,16),(13,16),(15,17),(17,18),(16,18),(11,19),(10,20),(14,21),(13,22),(8,23),(18,24),(17,25),(10,26),(11,27),(12,28)]
