import sys
from collections import deque
sys.setrecursionlimit(10**7)
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return map(int,sys.stdin.readline().rstrip().split())
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def LI2(): return list(map(int,sys.stdin.readline().rstrip()))
def S(): return sys.stdin.readline().rstrip()
def LS(): return list(sys.stdin.readline().rstrip().split())
def LS2(): return list(sys.stdin.readline().rstrip())


N = I()
Graph = [[] for _ in range(N+1)]
deg = [0]*(N+1)  # deg[i] = 頂点iの次数
for _ in range(N-1):
    a,b = MI()
    Graph[a].append(b)
    Graph[b].append(a)
    deg[a] += 1
    deg[b] += 1

count = [0]*N  # count[i] = 次数iの頂点数
for i in range(1,N+1):
    count[deg[i]] += 1

c = sum(count[3:])
if c == 0:
    print('Yes')
    exit()
if c >= 2:
    print('No')
    exit()

start = 0
for i in range(1,N+1):
    if deg[i] >= 3:
        start = i
        break

dist = [-1]*(N+1)
dist[start] = 0
deq = deque([start])
while deq:
    i = deq.pop()
    for j in Graph[i]:
        if dist[j] == -1:
            dist[j] = dist[i]+1
            deq.appendleft(j)

leaf = []
for i in range(1,N+1):
    if deg[i] == 1:
        leaf.append(i)

X = set([dist[i] for i in leaf])
if len(X) == 1:
    print('Yes')
else:
    print('No')