[(0,1),(0,2),(2,3),(2,4),(3,5),(4,6),(5,6),(4,7),(7,8),(8,9),(5,9),(8,10),(6,10),(1,11),(3,11),(10,12),(12,13),(11,13),(7,14),(1,14),(12,15),(15,16),(16,17),(15,18),(9,18),(17,19),(13,19),(14,20),(17,20),(16,21),(21,22),(20,23),(18,23),(21,24),(23,25),(22,26),(22,27),(19,28)]
[(0,1),(1,2),(0,2),(2,3),(1,3),(3,4),(4,5),(4,6),(5,7),(6,8),(7,8),(7,9),(9,10),(6,11),(11,12),(10,13),(8,13),(10,14),(12,14),(5,15),(9,16),(13,17),(15,18),(11,18),(14,19),(16,19),(17,20),(19,21),(12,21),(20,22),(15,22),(16,23),(20,23),(18,24),(17,25),(21,26),(22,27),(23,28)]
