import heapq
from collections import defaultdict

def dijkstra(s):
    global N, P, Leaf
    D = [float('inf')] * N
    D[s] = 0
    q = [(0, s)]
    heapq.heapify(q)
    while len(q) > 0:
        cost, c = heapq.heappop(q)
        if cost > D[c]:
            continue
        for p in Edge[c]:
            if D[p] > D[c] + 1:
                D[p] = D[c] + 1
                heapq.heappush(q, (D[p], p))
    
    res = -1
    for e in Leaf:
        if res < 0:
            res = D[e]
        elif res != D[e]:
            return -1
    return res

N = int(input())

Edge = defaultdict(list)

for _ in range(N-1):
    v, u = map(int, input().split())
    Edge[v-1].append(u-1)
    Edge[u-1].append(v-1)
    
Leaf = []
Start = -1
NG = False
for k, v in Edge.items():
    if len(v) == 1:
        Leaf.append(k)
    elif len(v) >= 3:
        if Start < 0:
            Start = k
        else:
            NG = True
            break

if NG:
    print('No')
elif Start < 0:
    print('Yes')
else:
    print('Yes' if dijkstra(Start) >= 0 else 'No')