n = int(input())
g = [[] for _ in range(n)]
for _ in range(n-1):
    a,b = map(int,input().split())
    g[a-1].append(b-1)
    g[b-1].append(a-1)

leaf = [v for v in range(n) if len(g[v]) == 1]
three = [v for v in range(n) if len(g[v]) >= 3]

if len(three) >= 2:
    print("No")
    exit()
if len(three) == 0:
    print("Yes")
    exit()
s = three[0]
dist = [-1]*n
dist[s] = 0
parent = [-1]*n
q = [s]
for v in q:
    for c in g[v]:
        if c == parent[v]:
            continue
        parent[c] = v
        dist[c] = dist[v] + 1
        q.append(c)

v = leaf[0]
print("Yes" if all(dist[v] == dist[vi] for vi in leaf) else "No")