import sys
from collections import deque

input = sys.stdin.buffer.readline


def bfs(N, T, s, return_all_dist=False):
    dist = [None] * N
    dist[s] = 0
    d = deque([s])
    while d:
        v = d.popleft()
        dx = dist[v] + 1
        for x in T[v]:
            if dist[x] is not None:
                continue
            dist[x] = dx
            d.append(x)
    if return_all_dist:
        return dist
    else:
        max_dist = max(dist)
        return dist.index(max_dist), max_dist


def med_tree(N, T):
    u, _ = bfs(N, T, 0)
    v, max_dist = bfs(N, T, u)
    if max_dist % 2:
        return None
    med_dist = max_dist // 2
    dist_u = bfs(N, T, u, return_all_dist=True)
    dist_v = bfs(N, T, v, return_all_dist=True)
    for i, (du, dv) in enumerate(zip(dist_u, dist_v)):
        if du == dv == med_dist:
            return i


def solve(N, T):
    leaves_num = sum([len(t) == 1 for t in T])
    if leaves_num == 2:
        # 直線
        return True
    med = med_tree(N, T)
    if med is None:
        return False
    return len(T[med]) == leaves_num


N = int(input())
T = [[] for _ in range(N)]
for _ in range(N - 1):
    a, b = (int(x) - 1 for x in input().split())
    T[a].append(b)
    T[b].append(a)

print("Yes" if solve(N, T) else "No")