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