leaf = set()
def dfs(cv, pv, G, d):
    is_leaf = True
    for nv in G[cv]:
        if nv == pv: continue
        dfs(nv, cv, G, d + 1)
        is_leaf = False
    
    if is_leaf: leaf.add(d)

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

deg3 = 0
cv = -1
for i in range(n):
    if 3 <= len(G[i]):
        deg3 += 1
        cv = i

if deg3 >= 2:
    print("No")
    exit()

if deg3 == 0:
    print("Yes")
    exit()

dfs(cv, -1, G, 0)

if len(leaf) == 1:
    print("Yes")
else:
    print("No")