import sys
sys.setrecursionlimit(10 ** 7)
n = int(input())
if n <= 3:
    print('Yes')
    exit()
deg = [0] * n
to = [[] for _ in range(n)]
for _ in range(n - 1):
    a, b = map(int, input().split())
    a -= 1
    b -= 1
    to[a].append(b)
    to[b].append(a)
    deg[a] += 1
    deg[b] += 1
imx = max(range(n), key=lambda i: deg[i])
if deg[imx] == 2:
    print('Yes')
    exit()
if any(i != imx and deg[i] >= 3 for i in range(n)):
    print('No')
    exit()
depth = [0] * n
def dfs(u, p=-1):
    if p >= 0:
        depth[u] = depth[p] + 1
    for v in to[u]:
        if v == p:
            continue
        dfs(v, u)
dfs(imx)
d = -1
ok = True
for i in range(n):
    if deg[i] == 1:
        if d == -1:
            d = depth[i]
        elif d != depth[i]:
            ok = False
            break
ans = 'Yes' if ok else 'No'
print(ans)