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