#include<iostream>
#include<string>
#include<algorithm>
#include<vector>
#include<cmath>
#include <limits>

using namespace std;

int main(){
	int n,a[21],b[21],c[21];
	int ans=0;
	
	cin >> n;
	
	for(int i=0;i<n;i++){
		cin >> a[i];
	}
	for(int i=0;i<n;i++){
		cin >> b[i];
	}
	for(int i=0;i<n-1;i++){
		cin >> c[i];
	}
	
	for(int i=0;i<n;i++){
		if(i==0)ans += b[a[0]-1];
		else if(a[i] - a[i-1] == 1)ans = ans + b[a[i]-1] + c[a[i]-2];
		else ans = ans + b[a[i]-1);
	}
	
	cout << ans << endl;
	
	return 0;
}