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.*;
import java.util.*;
import java.util.List;

public class C {
    private static StringTokenizer st;
    private static BufferedReader br;
    public static long MOD = 1000000007;

    public static void print(Object x) {
        System.out.println(x + "");
    }
    public static String join(List<?> x, String space) {
        StringBuilder sb = new StringBuilder();
        for (Object elt : x) {
            sb.append(elt);
            sb.append(space);
        }
        return sb.toString();
    }

    public static String nextToken() throws IOException {
        while (st == null || !st.hasMoreTokens()) {
            String line = br.readLine();
            st = new StringTokenizer(line.trim());
        }
        return st.nextToken();
    }
    public static int nextInt() throws IOException {
        return Integer.parseInt(nextToken());
    }
    public static long nextLong() throws IOException {
        return Long.parseLong(nextToken());
    }
    public static List<Integer> nextInts(int N) throws IOException {
        List<Integer> ret = new ArrayList<Integer>();
        for (int i = 0; i < N; i++) {
            ret.add(nextInt() - 1);
        }
        return ret;
    }

    public static double solve(int n, int m, double[] expected, char[][] strings, int guessed) {
        if (expected[guessed] == -1) {
            for (int guess = 0; guess < m; guess++) {
                if (((guessed >> guess) & 1) == 1) continue;
                int nextGuessed = guessed | (1 << guess);
                solve(n, m, expected, strings, nextGuessed);
            }
        }
        return expected[guessed];
    }

    public static void main(String[] args) throws IOException {
        br = new BufferedReader(new InputStreamReader(System.in));

        int n = nextInt();
        int m = nextInt();
        int[] weight = new int[n];
        for (int i = 0; i < n; i++) weight[i] = nextInt();
        int[] b = new int[m];
        for (int i = 0; i < m; i++) b[i] = nextInt() - 1;
        List<Integer> bookOrder = new ArrayList<Integer>();
        for (int i = 0; i < m; i++)
            if (!bookOrder.contains(b[i]))
                bookOrder.add(b[i]);
        for (int i = 0; i < n; i++)
            if (!bookOrder.contains(i))
                bookOrder.add(i);

        int total = 0;
        for (int i = 0; i < m; i++) {
            for (int j = 0; ; j++) {
                if (bookOrder.get(j) == b[i]) {
                    bookOrder.remove(j);
                    bookOrder.add(0, b[i]);
                    break;
                }
                total += weight[bookOrder.get(j)];
            }
        }
        print(total);
    }
}
