N = int(input())

G = [[] for _ in range(N)]
for _ in range(N- 1):
	u,v = map(int,input().split())
	u -= 1
	v -= 1
	G[u].append(v)
	G[v].append(u)
	
dp = [[0] * 2 for _ in range(N)]
stack = [(0,-1),(~0,-1)]
ans = 0
while stack:
	now,p = stack.pop()
	if now < 0:
		now = ~now
		for v in G[now]:
			if v != p:
				stack.append((v,now))
				stack.append((~v,now))
	else:
		t1 = 0
		t2 = 0
		for v in G[now]:
			if v != p:
				dp[now][0] += 1
				dp[now][1] += dp[v][0]
				t1 = dp[v][0]
				t2 = dp[v][1]
				
				ans += 1 + dp[v][0] + dp[v][1]
		tmp = 0
		for v in G[now]:
			if v != p:
				tmp += (t1 - dp[v][0])
				tmp += (t2 - dp[v][1])
		ans += tmp // 2
print(ans)