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