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.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;
import java.util.Map.Entry;

public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        Scanner sc = new Scanner(br);
        int books = sc.nextInt();
        int elements = sc.nextInt();
        int weight[] = new int[books + 1];
        for (int i = 1; i <= books; i++) {
            weight[i] = sc.nextInt();
        }
        int input[] = new int[elements];
        for (int i = 0; i < elements; i++) {
            input[i] = sc.nextInt();
        }
        List<Integer> myList = new ArrayList<Integer>(elements);
        for (int i : input) {
            if (!myList.contains(i)) {
                myList.add(i);
            }
        }
        for (int i = 1; i <= books; i++) {
            if (!myList.contains(i)) {
                myList.add(i);
            }
        }
        List<Integer> linkedList = new LinkedList<Integer>();
        for (int i = myList.size() - 1; i >= 0; i--) {
            linkedList.add(myList.get(i));
        }
        int answer = 0;
        int k = 0;
        boolean found;
        for (int i = 0; i < input.length; i++) {
            // System.out.println(i);
            Iterator<Integer> it = linkedList.iterator();
            found = false;
            while (it.hasNext()) {
                k = it.next();
                if (k == input[i]) {
                    found = true;
                    it.remove();
                    continue;
                }
                if (found) {
                    // System.out.print("k=" + k + " " + arr[k].weight + " ");
                    answer = answer + weight[k];
                }
            }
            linkedList.add(input[i]);
            // System.out.println();
        }
        System.out.println(answer);
    }
}