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