n = gets.to_i
a = gets.split.map(&:to_i)
b = gets.split.map(&:to_i)
c = gets.split.map(&:to_i)
ans = 0
pre = 100000
a.each do |dish|
  ans += b[dish - 1]
  ans += c[dish - 2] if dish == pre + 1
  pre = dish
end
puts ans