N = gets.to_i
A = gets.split.map(&:to_i)
B = gets.split.map(&:to_i)
G = Array.new(N + 1){ [] }

def max(a,b); a > b ? a : b; end
class << G
  def bfs_order
    stack = [1]
    used = Array.new(size)
    order = []
    until stack.empty?
      u = stack.pop
      
      next if used[u]
      
      used[u] = order.size
      order << u
      self[u].each do |v|
        next if used[v]
        stack << v
      end
    end
    order.reverse
  end
end

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

order = G.bfs_order

dp0 = Array.new(N + 1)
dp1 = Array.new(N + 1)
used = Array.new(N + 1)

order.each do |u|
  used[u] = true
  
  dp0[u] = G[u].map do |v|
    next 0 if !used[v]
    max(dp0[v], dp1[v])
  end.sum + A[u - 1]
  
  dp1[u] = G[u].map do |v|
    next 0 if !used[v]
    max(dp1[v] + B[v - 1] + B[u - 1], dp0[v])
  end.sum
end

puts max(dp0[1], dp1[1])