import sys
from collections import defaultdict, Counter, deque
from itertools import permutations, combinations, product, combinations_with_replacement, groupby, accumulate
import operator
from math import sqrt, gcd, factorial
#import scipy.optimize as optimize
#from math import isqrt, prod,comb  # python3.8用(notpypy)
#from bisect import bisect_left,bisect_right
#from functools import lru_cache,reduce
#from heapq import heappush,heappop,heapify,heappushpop,heapreplace
#import numpy as np
#import networkx as nx
#from networkx.utils import UnionFind
#from numba import njit, b1, i1, i4, i8, f8
#from scipy.sparse import csr_matrix
#from scipy.sparse.csgraph import shortest_path, floyd_warshall, dijkstra, bellman_ford, johnson, NegativeCycleError
#numba例 @njit(i1(i4[:], i8[:, :]),cache=True) 引数i4配列、i8 2次元配列,戻り値i1
def input(): return sys.stdin.readline().rstrip()
def divceil(n, k): return 1+(n-1)//k  # n/kの切り上げを返す
def yn(hantei, yes='Yes', no='No'): print(yes if hantei else no)

def main():
    mod = 10**9+7
    mod2 = 998244353
    n=int(input())
    graph = [[] for _ in range(n)]
    
    for i in range(n-1):
        a, b = map(lambda x: int(x)-1, input().split())
        graph[a].append(b)
        graph[b].append(a)
    
    dist = [-1] * (n+1)
    for i in range(n):
        if len(graph[i])>1:
            root=i
            break
    dist[root] = 0
    
    d = deque()
    d.append(root)
    
    while d:
        v = d.popleft()
        for i in graph[v]:
            if dist[i] != -1:
                continue
            dist[i] = dist[v] + 1
            d.append(i)


    dist2 = [-1] * (n+1)
    md=dist.index(max(dist))
    dist2[md] = 0
    
    d = deque()
    d.append(md)
    
    while d:
        v = d.popleft()
        for i in graph[v]:
            if dist2[i] != -1:
                continue
            dist2[i] = dist2[v] + 1
            d.append(i)
    
    
    ans=set()
    for i in range(n):
        if len(graph[i])==1 and i!=root:
            ans.add(dist[i])
    yn(len(ans)==1 or max(dist2)==1)
    
    


if __name__ == '__main__':
    main()