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