from collections import deque

N = int(input())
G = [list() for _ 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)

s1, s2 = [], []
for i in range(N):
    if len(G[i])==1:
        s1.append(i)
    else:
        s2.append(i)

if len(s1)==2:
    exit(print('Yes'))
else:
    cnt = 0
    s3 = []
    for s in s2:
        if len(G[s])>=3:
            cnt += 1
            s3.append(s)
    if cnt>1:
        exit(print('No'))
    else:
        d = deque([s3[0]])
        dis = [-1]*N
        dis[s3[0]] = 0
        while d:
            v = d.popleft()
            for nex in G[v]:
                if dis[nex]==-1:
                    dis[nex]= dis[v]+1
                    d.append(nex)
        dd = []
        for a in s1:
            dd.append(dis[a])
        if len(set(dd))==1:
            print('Yes')
        else:
            print('No')