import sys
input = sys.stdin.readline
from collections import *

def bfs():
    dist = [-1]*N
    dist[l[0]] = 0
    q = deque([l[0]])
    
    while q:
        v = q.popleft()
        
        for nv in G[v]:
            if dist[nv]==-1:
                dist[nv] = dist[v]+1
                q.append(nv)
    
    return dist

N = int(input())
deg = [0]*N
G = [[] for _ in range(N)]

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

if max(deg)<=2:
    print('Yes')
    exit()

l = []

for i in range(N):
    if deg[i]>=3:
        l.append(i)
    
if len(l)>=2:
    print('No')
    exit()

dist = bfs()
dl = []

for i in range(N):
    if deg[i]==1:
        dl.append(dist[i])

if dl==[dl[0]]*len(dl):
    print('Yes')
else:
    print('No')