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