import sys
def input():
	return sys.stdin.buffer.readline()[:-1]

n = int(input())
adj = [[] for _ in range(n)]
for _ in range(n-1):
	a, b = map(int, input().split())
	adj[a-1].append(b-1)
	adj[b-1].append(a-1)

for i in range(n):
	if len(adj[i]) == 1:
		leaf = i
		break

depth = [1000000 for _ in range(n)]
depth[leaf] = 0
st = [(leaf, -1)]
while st:
	i, p = st.pop()
	if len(adj[i]) == 1 and i != leaf:
		other = i
		break
	for j in adj[i]:
		if j == p:
			continue
		else:
			depth[j] = depth[i] + 1
			st.append((j, i))

if depth[other] % 2 == 1:
	print("Yes" if max(len(adj[i]) <= 2 for i in range(n)) else "No")
	sys.exit()

for i in range(n):
	if depth[i] == depth[other] // 2:
		center = i
		assumed = depth[i]
		break

depth = [1000000 for _ in range(n)]
depth[center] = 0
st = [(center, -1)]
while st:
	i, p = st.pop()
	if len(adj[i]) == 1 and depth[i] != assumed:
		print("No")
		break
	for j in adj[i]:
		if j == p:
			continue
		else:
			depth[j] = depth[i] + 1
			st.append((j, i))
else:
	for i in range(n):
		if i != center and len(adj[i]) > 2:
			print("No")
			break
	else:
		print("Yes")