from collections import deque

n=int(input())
E=[[] for _ in range(n+1)]
for _ in range(n-1):
	a,b=map(int,input().split())
	E[a].append(b)
	E[b].append(a)
	
ans=0
for i in range(1,n+1):
	D=[10**9]*(n+1)
	D[i]=0
	q=deque([(i)])
	while q:
		x=q.popleft()
		for e in E[x]:
			if D[e]>D[x]+1:
				D[e]=D[x]+1
				if D[e]<=3:
					q.append(e)
					ans+=1
print(ans//2)