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