n = STDIN.gets.to_i
a = STDIN.gets.split(" ").map(&:to_i)
b = STDIN.gets.split(" ").map(&:to_i)
c = STDIN.gets.split(" ").map(&:to_i)

prev = -1
manzoku = 0
a.each do |eat|
  manzoku += b[eat-1]

  manzoku += c[prev-1] if prev + 1 == eat
  prev = eat
end

puts manzoku