from collections import deque

n = int(input())
e = [[] for i in range(n+1)]
for i in range(n-1):
    a,b = map(int,input().split())
    e[a].append(b)
    e[b].append(a)

c = 0
cand = []
ind = 0
for i in range(1,n+1):
    if len(e[i]) == 1:
        cand.append(i)
    if len(e[i]) >= 3:
        c += 1
        ind = i
if c == 0:
    print("Yes")
    exit()
if c >= 2:
    print("No")
    exit()

dis = [10**10]*(n+1)
dis[ind] = 0
q = deque([ind])
while q:
    now = q.popleft()
    for nex in e[now]:
        if dis[nex] > dis[now]+1:
            dis[nex] = dis[now]+1
            q.append(nex)

d = dis[cand[0]]
for i in cand:
    if d != dis[i]:
        print("No")
        exit()
print("Yes")