from collections import defaultdict, deque


def main():
    def BFS(s):
        dist = [-1]*n
        q = deque([])
        q.append(s)
        dist[0] = 0
        while q:
            now = q.popleft()
            for to in d[now]:
                if dist[to] == -1:
                    dist[to] = dist[now] + 1
                    q.append(to)
        return dist
    n = int(input())
    d = defaultdict(list)
    for i in range(n-1):
        a, b = map(int, input().split())
        a -= 1
        b -= 1
        d[a].append(b)
        d[b].append(a)

    ends = []
    center = -1
    for i in range(n):
        if len(d[i]) == 1:
            ends.append(i)
        elif len(d[i]) >= 3:
            if center == -1:
                center = i
            else:
                return False
    if center == -1:
        return True
    length = -1
    dist = BFS(center)
    for end in ends:
        if length == -1:
            length = dist[end]
        elif length != dist[end]:
            return False
    return True


if main():
    print("Yes")
else:
    print("No")