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