import heapq
INF=10**9
def Dijkstra(graph, start):
  dist=[INF]*len(graph)
  parent=[INF]*len(graph)
  queue=[(0, start)]
  dist[start]=0
  while queue:
    path_len, v=heapq.heappop(queue)
    if path_len==dist[v]: 
      for w in graph[v]:
        if dist[w]>path_len+1:
          parent[w]=v
          heapq.heappush(queue, (path_len+1, w))
          dist[w]=path_len+1    
  return (dist,parent)
n=int(input())

graph=[]
for i in range(n):
  graph.append([])
for i in range(n-1):
  a,b=map(int,input().split())
  graph[a-1].append(b-1)
  graph[b-1].append(a-1)
flag=0
fail=0
for i in range(n):
  if len(graph[i])>2:
    if flag==1:
      fail=1
    flag=1
    start=i
if fail:
  print('No')
  exit()
if flag==0:
  print('Yes')
  exit()
dist,parent=Dijkstra(graph,start)
k=set()
for i in range(n):
  if len(graph[i])==1:
    k.add(dist[i])
if len(k)==1:
  print('Yes')
else:
  print('No')