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