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