N = gets.to_i
A = gets.split.map(&:to_i)
B = gets.split.map(&:to_i)
C = gets.split.map(&:to_i)

score = 0
keep = Float::INFINITY

A.each do |i|
  score += B[i - 1]
  if keep + 1 == i
    score += C[keep - 1]
  end
  keep = i
end

puts score