N = gets.to_i
E = Hash.new { |h, k| h[k] = [] }

(N - 1).times do
  a, b = gets.split.map(&:to_i)
  E[a] << b
  E[b] << a
end

cnt = E.map { |_, list| list.size }.count { |x| x >= 3 }
if cnt >= 2
  puts 'No'
  exit
elsif cnt == 0
  puts 'Yes'
  exit
end

root = (1..N).find { |v| E[v].size >= 3 }
counter = Hash.new(0)

def bfs(root, counter)
  queue = []
  queue << [root, 0]
  visited = Array.new(N + 1, false)

  until queue.empty?
    v, dist = queue.shift

    next if visited[v]
    visited[v] = true

    if dist > 0 && E[v].size == 1
      counter[dist] += 1
    end

    E[v].each do |u|
      queue << [u, dist + 1]
    end
  end
end

bfs(root, counter)

if counter.size >= 2
  puts 'No'
else
  puts 'Yes'
end