from collections import deque

n = int(input())
G = [[] for _ in range(n)]
for _ in range(n-1):
    a,b = map(int,input().split())
    a -= 1
    b -= 1
    G[a].append(b)
    G[b].append(a)

l = []
for i in range(n):
    if len(G[i]) >= 3:
        l.append(i)

if len(l) >= 2:
    print("No")
elif len(l) == 0:
    print("Yes")
else:
    s = set()
    q = deque()
    q.append((l[0],-1,0))
    while q:
        cur ,par ,dist = q.popleft()
        isleaf = True
        for nx in G[cur]:
            if nx != par:
                isleaf = False
                q.append((nx,cur,dist+1))
        if isleaf:
            s.add(dist)
    if len(s) == 1:
        print("Yes")
    else:
        print("No")