import java.util.*

fun main(args: Array<String>) {
    val scanner = Scanner(System.`in`)
    val n = scanner.nextInt()
    val a = IntArray(n)
    val b = IntArray(n)
    val c = IntArray(n-1)
    for(i in 0..n-1) {
        a[i] = scanner.nextInt()
    }
    for(i in 0..n-1) {
        b[i] = scanner.nextInt()
    }
    for(i in 0..n-2) {
        c[i] = scanner.nextInt()
    }
    var sum = 0
    var index = 99
    for(i in 0..n-1){
        sum += b[a[i]-1]
        if(a[i]-1 ===  index) sum += c[a[i]-2]
        index = a[i]
    }
    println(sum)
}