N = int(input())
deg = [0] * N
adj = [[] for i in range(N)]
for i in range(N - 1):
    a, b = map(int, input().split())
    a -= 1
    b -= 1
    deg[a] += 1
    deg[b] += 1
    adj[a].append(b)
    adj[b].append(a)
aiueo = len(deg) - deg.count(2) - deg.count(1)
if aiueo > 1:
    print("No")
    exit()
if aiueo == 0:
    print("Yes")
    exit()
from collections import deque
r = deg.index(max(deg))
dep = [-1] * N
dep[r] = 0
qu = deque([r])
while len(qu):
    v = qu.popleft()
    for nv in adj[v]:
        if dep[nv] == -1:
            dep[nv] = dep[v] + 1
            qu.append(nv)
d = -1
for i in range(N):
    if deg[i] != 1:
        continue
    if d != -1 and d != dep[i]:
        print("No")
        exit()
    d = dep[i]
print("Yes")