import java.util.*

fun main(args: Array<String>) {

    val n = Integer.parseInt(readNext())

    val a = readNext().split(" ").map { Integer.parseInt(it) }

    val b = readNext().split(" ").map { Integer.parseInt(it) }

    val c = readNext().split(" ").map { Integer.parseInt(it) }
    var result = 0
    var pren = 0;
    for (i in 0..n - 1) {
        val n = a[i]
        result += b[n -1]
        if (pren + 1 == n && i != 0) {
            result += c[pren-1]
        }
        pren = n

    }
    println(result)
}
fun readNext(): String {
    return readLine()!!
}