50 50
75 71 23 37 28 23 69 75 5 62 3 11 96 100 13 50 57 51 8 90 4 6 84 27 11 89 95 81 10 62 48 52 69 87 97 95 30 74 21 42 36 64 31 80 81 50 56 53 33 99
26 30 5 33 35 29 6 15 36 17 32 16 14 1 29 34 22 40 12 42 38 48 39 50 13 47 18 43 10 8 49 45 11 31 21 37 46 28 20 41 2 7 9 24 27 23 3 44 15 14
 10 10
61 59 97 16 2 94 57 48 91 93
2 8 6 5 3 1 3 4 9 10
 2 1
1 2
1
 3 3
10 20 30
1 2 3
 50 60
86 57 45 93 17 12 40 10 47 80 18 80 3 9 6 55 13 99 5 76 4 70 100 55 27 91 71 3 65 93 41 74 80 56 90 50 58 13 71 9 47 52 26 73 72 21 15 81 88 28
40 32 5 16 49 23 3 17 14 10 1 15 1 21 28 22 13 45 12 25 44 48 46 32 36 43 11 8 49 7 7 35 10 14 39 4 42 10 30 27 1 17 31 15 8 41 44 33 25 26 19 18 29 37 50 6 36 38 47 9
 2 7
20 30
1 1 1 2 2 2 2
 2 2
10 12
2 1
 5 1
16 87 36 16 81
3
 2 3
20 30
1 1 1
 2 10
39 26
1 1 2 2 2 2 2 2 1 2

63929
 2137
 0
 40
 62514
 20
 12
 0
 0
 104

import java.util.*;
import java.io.*;
public class lifting {
	public static void main(String[] args) throws IOException{
		BufferedReader f = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st = new StringTokenizer(f.readLine());
		int N = Integer.parseInt(st.nextToken());
		int M = Integer.parseInt(st.nextToken());
		int[] weights = new int[N];
		st = new StringTokenizer(f.readLine());
		for(int i=0;i<N;i++){
			weights[i] = Integer.parseInt(st.nextToken());
			
		}
		int[] calls = new int[M];
		TreeMap<Integer, Integer> firstInstanceOf = new TreeMap<Integer, Integer>();
		st = new StringTokenizer(f.readLine());
		for(int i=0;i<M;i++){
			calls[i] = Integer.parseInt(st.nextToken())-1;
		}
		boolean[] seen = new boolean[N];
		for(int i=0;i<M;i++){
			if(!seen[calls[i]]){
				firstInstanceOf.put(i, calls[i]);
				seen[calls[i]] = true;
			}
		}
		ArrayList<Integer> a = new ArrayList<Integer>();
		for(Integer i : firstInstanceOf.keySet()){
			a.add(firstInstanceOf.get(i));
		}
		Collections.reverse(a);
//		System.out.println(a);
		int ans = 0;
		for(int i=0;i<M;i++){
			int book = calls[i];
			int r = a.indexOf((Integer) book);
//			int now = 0;
			for(int i2=r+1;i2<a.size();i2++){
				ans += weights[a.get(i2)];
			}
//			System.out.println(a);
//			System.out.println(now);
//			ans += now;
			a.remove(r);
			a.add(book);
//			System.out.println(a);
		}
		System.out.println(ans);
	}
}
