from collections import deque
n=int(input())
g=[[] for _ in range(n)]
in_num=[0]*n
for _ in range(n-1):
    a,b=map(int,input().split())
    g[a-1].append(b-1)
    g[b-1].append(a-1)
cnt_3=0
for i in range(n):
    if len(g[i])>=3:
        cnt_3+=1
if cnt_3>=2:
    print('No')
elif cnt_3==0:
    print('Yes')
else:
    q=deque()
    cnt=0
    for i in range(n):
        if len(g[i])==1:
            q.append((i,-1,0))
            cnt+=1
            if cnt>10:
                break
    D=set()
    while q:
        now,pre,d=q.popleft()
        for to in g[now]:
            if to==pre:
                continue
            if len(g[to])==1:
                D.add(d+1)
                continue
            q.append((to,now,d+1))
    if len(D)==1:
        print('Yes')
    else:
        print('No')