[(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),(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)]
