[(0,1),(0,2),(1,2),(1,3),(2,4),(3,4),(4,5),(3,5),(5,6),(6,7),(6,8),(7,9),(7,10),(8,11),(8,12)]
[(0,1),(0,2),(2,3),(3,4),(1,4),(3,5),(1,5),(4,6),(5,6),(6,7),(7,8),(2,9),(8,10),(8,11),(7,12)]
