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



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
    
Q = deque()
dist = dict()
for i in range(N):
    dist[i] = -1
par = [-1] * N
for i in range(N):
    if D[i] == 1:
        Q.append(i)
        dist[i] = 0
        
while Q:
    u = Q.popleft()
    for v in G[u]:
        if v == par[u]:
            continue
        if dist[v] != -1:
            if -1 in dist:
                print("No")
                exit()
            if dist[v] == dist[u]:
                print("No")
                exit()
            continue
        dist[v] = dist[u] + 1
        par[v] = u
        Q.append(v)
print("Yes")