n=int(input())
ab=[list(map(int,input().split())) for _ in range(n-1)]
ki=[[] for _ in range(n)]
for a,b in ab:
  a,b=a-1,b-1
  ki[a].append(b)
  ki[b].append(a)
deg1=[v for v in range(n) if len(ki[v])==1]
v0=deg1[0]
from collections import deque
todo=deque([v0])
seen=[-1]*n
seen[v0]=0
while todo:
  v=todo.popleft()
  for nv in ki[v]:
    if seen[nv]==-1:
      seen[nv]=seen[v]+1
      todo.append(nv)
v1=v
todo=deque([v1])
seen=[-1]*n
seen[v1]=0
while todo:
  v=todo.popleft()
  for nv in ki[v]:
    if seen[nv]==-1:
      seen[nv]=v
      todo.append(nv)
v2=v
dary=[v2]
while dary[-1]!=v1:
  dary.append(seen[dary[-1]])
d=len(dary)
if d%2==1:
  vm=dary[d//2]
  if n==1+len(ki[vm])*(d//2):
    print('Yes')
  else:
    print('No')
else:
  if n==len(dary):
    print('Yes')
  else:
    print('No')