G = Graph({
1 : [2,5],
2 : [3,6],
3 : [4],
4 : [5],
5 : [1,6],
6 : [2,7],
8 : [1]
})
G.is_planar()
G.complement().is_planar()

D = Graph({
1 : [10,6],
2 : [9,11,5],
3 : [8,10,12],
4 : [7,11],
5 : [2,10,14],
6 : [1,9,15,13],
7 : [4,12,14,16],
8 : [3,11,15],
9 : [2,6,14],
10 : [1,3,5,13],
11 : [4,2,8,16],
12 : [3,7,15],
13 : [6,10],
14 : [5,7,9],
15 : [8,6,12],
16 : [7,11]
})

for v in range(1,16+1):
	DD = D.copy()
	DD.delete_vertex(v)
	print(DD.is_connected())