from collections import defaultdict, 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)

s = []
for i in range(N):
    if len(G[i])==1:
        s.append(i)
if len(s)==2:
    print('Yes')
else:
    dis = [-1]*N
    pre = [-1]*N
    d = deque()
    d.append(s[0])
    dis[s[0]] = 0
    while d:
        v = d.popleft()
        for nex in G[v]:
            if dis[nex]==-1:
                dis[nex]=dis[v]+1
                pre[nex] = v
                d.append(nex)
    if dis[s[1]]%2==1:
        exit(print('No'))
    else:
        dd = dis[s[1]]//2
        nn = dis[s[1]]
        v = s[1]
        while nn>dd:
            v = pre[v]
            nn = dis[v]
        d.append(v)
        dis2 = [-1]*N
        dis2[v] = 0
        while d:
            ver = d.popleft()
            for nex in G[ver]:
                if dis2[nex]==-1:
                    dis2[nex]=dis2[ver]+1
                    d.append(nex)
        for ss in s:
            if dis2[ss]!=nn:
                print('No')
                exit()
        print('Yes')