import sys
readline = sys.stdin.readline
from collections import deque


def bfs(G, s, N):
    Q = deque([])
    dist = [-1] * N
    par = [-1] * N
    dist[s] = 0
    for u in G[s]:
        par[u] = s
        dist[u] = 1
        Q.append(u)

    while Q:
        u = Q.popleft()
        for v in G[u]:
            if dist[v] != -1:
                continue
            dist[v] = dist[u] + 1
            par[v] = u
            Q.append(v)
            
    return dist


N = int(readline())
G = [[] for i in range(N)]
D = [0] * N
for i in range(N - 1):
    A, B = map(int, readline().split())
    A, B = A - 1, B - 1
    G[A].append(B)
    G[B].append(A)
    D[A] += 1
    D[B] += 1
    
one = []
for i in range(N):
    if D[i] == 1:
        one.append(i)
        
D1 = bfs(G, one[0], N)
S1 = set()
for a in one:
    if D1[a] == 0:
        continue
    S1.add(D1[a])
if len(S1) != 1:
    print("No")
    exit()
    
D1 = bfs(G, one[1], N)
S1 = set()
for a in one:
    if D1[a] == 0:
        continue
    S1.add(D1[a])
if len(S1) != 1:
    print("No")
    exit()
    
print("Yes")