import queue

n = int(input())
adj = [[] for _ in range(n + 1)]
for i in range(n - 1):
    a, b = map(int, input().split())
    adj[a].append(b)
    adj[b].append(a)
lst = []
for i in range(1, n + 1):
    if len(adj[i]) >= 3:
        lst.append(i)
if len(lst) >= 2:
    print("No")
elif len(lst) == 0:
    print("Yes")
else:
    lens = set([])
    que = queue.Queue()
    que.put((lst[0], -1, 0))
    while not que.empty():
        v, p, d = que.get()
        isleaf = True
        for w in adj[v]:
            if w != p:
                isleaf = False
                que.put((w, v, d + 1))
        if isleaf:
            lens.add(d)
    if len(lens) == 1:
        print("Yes")
    else:
        print("No")