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