import sys
sys.setrecursionlimit(1000000)
N = int(input())
G = {i:[] for i in range(1,N+1)}
for _ in range(N-1):
    a,b = map(int,input().split())
    G[a].append(b)
    G[b].append(a)
A = []
for i in range(1,N+1):
    if len(G[i])==1:
        A.append(i)
if len(A)==2:
    ans = "Yes"
else:
    from collections import deque
    u = A[0]
    dist = [-1]*(N+1)
    dist[u] = 0
    que = deque([u])
    while que:
        v = que.popleft()
        for i in G[v]:
            if dist[i]<0:
                dist[i] = dist[v]+1
                que.append(i)
    if dist[A[1]]%2==1:
        ans = "No"
    else:
        B = [A[0]]
        def dfs(i,p):
            global A,B
            if i==A[1]:
                return True
            for j in G[i]:
                if j==p:continue
                B.append(j)
                if dfs(j,i):
                    return True
                B.pop()
            return False
        dfs(A[0],-1)
        rt = B[len(B)//2]
        dist = [-1]*(N+1)
        dist[rt] = 0
        que = deque([rt])
        while que:
            u = que.popleft()
            for v in G[u]:
                if dist[v]<0:
                    dist[v] = dist[u]+1
                    que.append(v)
        d = dist[A[0]]
        ans = "Yes"
        for u in A:
            if dist[u] != d:
                ans = "No"
                break
print(ans)