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