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