[(0,1),(0,2),(2,3),(3,4),(1,5),(5,6),(4,7),(3,8),(1,9),(8,10),(10,11),(2,12),(9,13),(12,14),(5,15),(4,16),(7,16),(9,17),(11,18),(17,19),(14,20),(10,21),(8,22),(7,23),(6,24),(20,25),(17,26),(13,27),(6,28),(11,29),(20,30),(14,31),(12,32),(19,33),(15,34),(16,35),(19,36),(18,37),(18,38),(15,39),(13,40)]
[(0,1),(1,2),(0,3),(3,4),(3,5),(1,6),(5,7),(7,8),(6,8),(4,9),(4,10),(2,11),(11,12),(10,13),(5,14),(7,15),(11,16),(9,17),(15,18),(12,19),(14,20),(20,21),(17,22),(8,23),(9,24),(18,25),(16,26),(13,27),(6,28),(12,29),(19,30),(18,31),(14,32),(17,33),(20,34),(2,35),(13,36),(19,37),(16,38),(15,39),(10,40)]
