N = gets.to_i
AS = [nil] + gets.split.map(&:to_i)
BS = [nil] + gets.split.map(&:to_i)
CS = [nil] + gets.split.map(&:to_i)

ans = 0
prev_x = -1
for i in 1..N
  x = AS[i]
  ans += BS[x]
  if x == prev_x + 1
    ans += CS[prev_x]
  end
  prev_x = x
end
p ans