N = int(input())
G = [[] for i in range(N)]
indegree = [0] * N
for _ in range(N - 1):
    a,b = map(int,input().split())
    G[a - 1].append(b - 1)
    G[b - 1].append(a - 1)
    indegree[a - 1] += 1
    indegree[b - 1] += 1
    
uni = -1
for v in range(N):
    if indegree[v] > 2:
        if uni != -1:
            print("No")
            exit(0)
        uni = v

if uni == -1:
    print("Yes")
    exit(0)
    
stack = []
stack.append([uni, 0])
dist = [-1] * N
while stack:
    v, d = stack.pop()
    if dist[v] != -1:
        continue
    dist[v] = d
    for child in G[v]:
        if dist[child] != -1:
            continue
        stack.append([child, d + 1])

ds = set()        
for v in range(N):
    if indegree[v] == 1:
        ds.add(dist[v])
        
if len(ds) == 1:
    print("Yes")
else:
    print("No")