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