[(0,1),(1,2),(0,2),(1,3),(2,4),(3,5),(4,6),(5,7),(4,8),(7,8),(3,9),(6,9),(8,10),(5,11),(7,11),(6,12),(12,13),(10,13),(13,14),(12,15),(10,16),(9,17),(11,18)]
[(0,1),(1,2),(2,3),(0,3),(3,4),(1,4),(4,5),(2,6),(5,7),(7,8),(6,8),(7,9),(5,10),(10,11),(6,12),(9,12),(8,13),(11,13),(10,14),(9,15),(12,16),(11,17),(13,18)]
