[(0,1),(1,2),(0,2),(1,3),(2,4),(3,4),(4,5),(5,6),(5,7),(3,8),(8,9),(7,10),(9,11),(7,11),(10,12),(12,13),(13,14),(13,15),(10,16),(9,17),(11,18),(17,19),(12,19),(14,20),(16,21),(15,22),(6,22),(8,23),(20,24),(6,25),(16,26),(19,27),(27,28),(23,29),(25,30),(21,31),(21,32),(18,33),(17,34),(27,35),(26,36),(26,37),(25,38),(18,39),(28,40),(15,41),(22,42),(14,43),(24,44),(20,45),(23,46),(24,47),(28,48)]
[(0,1),(1,2),(0,3),(3,4),(2,4),(4,5),(5,6),(2,6),(1,7),(3,8),(7,9),(9,10),(10,11),(6,12),(5,13),(12,14),(8,15),(12,16),(11,16),(15,17),(16,18),(10,19),(17,20),(8,21),(18,22),(21,23),(14,24),(17,24),(7,25),(24,26),(21,26),(20,27),(19,28),(14,29),(25,30),(20,31),(28,32),(13,33),(26,34),(23,35),(18,36),(25,37),(9,38),(15,39),(19,40),(22,41),(11,42),(23,43),(27,44),(27,45),(13,46),(28,47),(22,48)]
