N = int(input())
G = [[] for _ in range(N)]
Gnum = [0] * N
for _ in range(N-1):
    a,b = map(int,input().split())
    a -= 1
    b -= 1
    G[a].append(b)
    G[b].append(a)
    Gnum[a] += 1
    Gnum[b] += 1

ha = 0
has = set()
for j in range(N):
    i = Gnum[j]
    if i == 1:
        ha += 1
        has.add(j)
import sys
if ha == 2:
    print('Yes')
    exit()
count = 0
center = -1
for j in range(N):
    i = Gnum[j]
    if 2 < i < ha:
        print('No')
        exit()
    if i == ha:
        count += 1
        center = j

if count != 1:
    print('No')
    exit()
dist = [0] * N
stack = [(center,-1)]
while stack:
    now,parent = stack.pop()
    for v in G[now]:
        if v == parent:continue
        dist[v] = dist[now] + 1
        stack.append((v,now))
s = set()
for v in has:
    s.add(dist[v])
if len(s) == 1:
    print('Yes')
else:
    print('No')
"""
print(s)
print(dist)
print(center)
"""