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