def dfs(N, adj, root):
    stack = [root]
    parent = [-1] * N
    parent[root] = root
    depth = [0] * N
    while stack:
        v = stack.pop()
        for nv in adj[v]:
            if parent[nv] == -1:
                parent[nv] = v
                depth[nv] = depth[v] + 1
                stack.append(nv)
    return parent, depth

def main():
    N = int(input())
    adj = [[] for _ in range(N)]
    for _ in range(N - 1):
        u, v = map(int, input().split())
        u -= 1; v -= 1
        adj[u].append(v)
        adj[v].append(u)

    _, depth_0 = dfs(N, adj, 0)
    root = max(range(N), key=lambda i: depth_0[i])
    parent, depth = dfs(N, adj, root)
    dist = max(depth)
    leaves = [v for v in range(N) if len(adj[v]) == 1]
    if dist % 2 == 1:
        if len(leaves) == 2:
            print("Yes")
        else:
            print("No")
    else:
        end = max(range(N), key=lambda i: depth[i])
        cent = end
        for _ in range(dist // 2):
            cent = parent[cent]
        _, dists = dfs(N, adj, cent)
        for l in leaves:
            if dists[l] != dist // 2:
                print("No")
                exit()
        print("Yes")    
    
main()