import java.io.{BufferedReader, InputStreamReader}

object Main {
  def main(args: Array[String]): Unit = {
    val in = new BufferedReader(new InputStreamReader(System.in))
    val _ = in.readLine().toInt
    val as = in.readLine().split("\\s+").map(_.toInt)
    val bs = in.readLine().split("\\s+").map(_.toInt)
    val cs = in.readLine().split("\\s+").map(_.toInt)

    System.out.println(
      bs.sum + as.zip(as.tail).filter {
        case (a1, a2) => a1 + 1 == a2
      }.map {
        case (a1, _) => cs.apply(a1 - 1)
      }.sum
    )
  }
}
