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