##unit2 video2 


def make_link(Graph,node1,node2):
	if node1 not in Graph:
		Graph[node1]={}
	Graph[node1][node2]=1
	
	if node2 not in Graph:
		Graph[node2]={}
	Graph[node2][node1]=1


Graph={}
numedges=5

for i in range(numedges):
	make_link(Graph,i,(i+1)%numedges)



print len(Graph)
