import sys
from collections import deque

input = sys.stdin.buffer.readline

n = int(input())
graph = [[] for _ in range(n)]
deg1 = [0] * n
deg2 = [0] * n
for _ in range(n - 1):
    a, b = map(int, input().split())
    a, b = a - 1, b - 1
    graph[a].append(b)
    graph[b].append(a)
    deg1[a] += 1
    deg1[b] += 1
root = -1
kouho = deque()
haji = []
dist1 = [-1] * n
done = [0] * n
for i in range(n):
    if deg1[i] != 1:
        root = i
    if deg1[i] == 1:
        haji.append(i)


def ok():
    print("Yes")
    exit()


def ng():
    print("No")
    exit()


if n == 2 or n==3:
    ok()
if root == -1:
    if n == 2:
        ok()
    else:
        ng()


# bfs
# print("kouho", kouho)

v = haji[0]
dist1[v] = 0
kouho.append(v)
while kouho:
    v = kouho.popleft()
    d = dist1[v]
    for u in graph[v]:

        if dist1[u] == -1:
            dist1[u] = d + 1
            kouho.append(u)

temp = dist1[haji[1]]

for v in haji[1:]:
    if dist1[v] != temp:
        ng()


dist2 = [-1] * n
v = haji[-1]
dist2[v] = 0
kouho.append(v)

while kouho:
    v = kouho.popleft()
    d = dist2[v]
    for u in graph[v]:

        if dist2[u] == -1:
            dist2[u] = d + 1
            kouho.append(u)

temp = dist2[haji[0]]

for v in haji[:-1]:
    if dist2[v] != temp:
        ng()

ok()