#include <bits/stdc++.h>
int main() {
  int dish[25];
  int points[55];
  int extra[55];
  int n;
  int max = 0;
  int ex = 0;
  scanf("%d", &n);
  for (int j = 0; j < n; ++j) {
    scanf("%d", &dish[j]);
  }
  for (int v = 0; v < n; ++v) {
    scanf("%d", &points[v]);
  }
  for (int h = 0; h < n - 1; ++h) {
    scanf("%d", &extra[h]);
  }
  for (int i = 0; i < n; ++i) {
    for (int k = 0; k < n; ++k) {
      if (dish[i] == k + 1) {
        max = max + points[k];
        if (i != 0 && dish[i] - dish[i - 1] == 1) {
          max = max + extra[ex];
          ex = ex + 1;
        }
      }
    }
  }
  printf("%d\n", max);
  return 0;
}
