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.*;

    public class Solution {
        StringTokenizer st;
        BufferedReader in;
        PrintWriter out;

        void solve() throws IOException {
            //in = new BufferedReader(new InputStreamReader(new FileInputStream("input.txt"), "ISO-8859-1"));
            //out = new PrintWriter(new OutputStreamWriter(new FileOutputStream("output.txt"), "ISO-8859-1"));
            in = new BufferedReader(new InputStreamReader(System.in));
            out = new PrintWriter(new OutputStreamWriter(System.out));
            Locale.setDefault(Locale.ENGLISH);

            int n = nextInt();
            int m = nextInt();

            int[] w = new int[n];
            for (int i = 0; i < n; i++) {
                w[i] = nextInt();
            }

            int[] b = new int[m];
            for (int i = 0; i < m; i++) {
                b[i] = nextInt() - 1;
            }


            boolean[] used = new boolean[n];
            int[][] a = new int[n][2];
            int pos = 0;
            for (int i = 0; i < m; i++) {
                if (!used[b[i]]) {
                    a[pos++] = new int[]{w[b[i]], b[i]};
                    used[b[i]] = true;
                }
            }

            int ans = 0;
            for (int i = 0; i < m; i++) {
                pos = 0;
                while (a[pos][1] != b[i]) {
                    ans += a[pos][0];
                    pos++;
                }

                int[] tmp = new int[]{a[pos][0], a[pos][1]};
                for (int j = pos; j > 0; j--) {
                    a[j] = a[j - 1];
                }
                a[0] = tmp;
            }

            out.print(ans);

            in.close();
            out.close();
        }

        public static void main(String[] args) throws IOException {
            new Solution().solve();
        }

        String next() throws IOException {
            while (st == null || !st.hasMoreTokens()) {
                st = new StringTokenizer(in.readLine());
            }
            return st.nextToken();
        }

        int nextInt() throws IOException {
            return Integer.parseInt(next());
        }

        long nextLong() throws IOException {
            return Long.parseLong(next());
        }

        double nextDouble() throws IOException {
            return Double.parseDouble(next());
        }
    }