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