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
    dist = [-1]*(N+1)
    dist[A[0]] = 0
    que = deque([A[0]])
    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)
        C1 = [[i,i] for i in range(N+1)]
        cnt = 0
        def dfs1(i,p):
            global cnt
            C1[i][0] = cnt
            cnt += 1
            for j in G[i]:
                if j==p:continue
                dfs1(j,i)
            C1[i][1] = cnt
            cnt += 1
        dfs1(rt,-1)
        C = [(C1[i][1]-C1[i][0])//2 for i in range(N+1)]
        C2 = {}
        for i in range(1,N+1):
            d = dist[i]
            if d not in C2:
                C2[d] = set()
            C2[d].add(C[i])
        ans = "Yes"
        for d in C2:
            if len(C2[d])>1:
                ans = "No"
                break
print(ans)