#include<bits/stdc++.h>

using namespace std;

int main(void){
  int N; cin >> N;
  int A[N], B[N], C[N-1];
  rep(i, N) cin >> A[i];
  rep(i, N) cin >> B[i];
  rep(i, N-1) cin >> C[i];
  int ans = 0;
  for(int i = 0; i < N; i++){
    ans += B[A[i]-1];
    if(i < N-1 && A[i]+1 == A[i+1]) ans += C[A[i]-1];
  }
  cout << ans << endl;
}