import collections
N = int(input())
lsg = [[] for i in range(N)]
lsj = [0]*(N)
for i in range(N-1):
    a,b = map(int, input().split())
    a -= 1
    b -= 1
    lsg[a].append(b)
    lsg[b].append(a)
    lsj[a] += 1
    lsj[b] += 1

n1 = 0
n2 = 0
n3 = 0
for i in range(N):
    if lsj[i] == 1:
        n1 += 1
    elif lsj[i] == 2:
        n2 += 1
    else:
        n3 += 1

if n1 == 2 and n2 == N-2: #直線
    print('Yes')
    exit()

if n3 >= 2: #分岐が複数×
    print('No')
    exit()

root = 0
for i in range(N):
    if lsj[i] >= 3:
        root = i
        break

d = collections.deque([root])
used = [False]*(N)
lsc = [float('INF')]*(N)
lsc[root] = 0
while d:
    n = d.popleft()
    if used[n]:
        continue
    used[n] = True
    for j in lsg[n]:
        if used[j]:
            continue
        if lsc[j] > lsc[n] + 1:
            lsc[j] = lsc[n] + 1
            d.append(j)

ll = []
for i in range(N):
    if lsj[i] == 1:
        ll.append(lsc[i])

cnt = len(collections.Counter(ll).keys())
if cnt == 1:
    print('Yes')
else:
    print('No')