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.Arrays;
import java.util.StringTokenizer;

public class ProbC {
    boolean eof;

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

    String next() {
        while (st == null || !st.hasMoreTokens()) {
            try {
                st = new StringTokenizer(br.readLine());
            } catch (Exception e) {
                eof = true;
                return "-1";
            }
        }
        return st.nextToken();
    }

    BufferedReader br;
    StringTokenizer st;
    PrintWriter out;

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

    void run() throws IOException {
        String name = "baseball";
        InputStream input = System.in;
        OutputStream output = System.out;
        try {
            File f = new File(name + ".in");
            if (f.exists() && f.canRead()) {
                input = new FileInputStream(f);
                output = new FileOutputStream(name + ".out");
            }
        } catch (Exception e) {
        }

        br = new BufferedReader(new InputStreamReader(input));
        out = new PrintWriter(output);

        solve();

        br.close();
        out.close();
    }

    void solve() {
        int n = nextInt();
        int m = nextInt();
        int[] w = new int[n];
        for (int i = 0; i < n; ++i) {
            w[i] = nextInt();
        }
        int[] a = new int[m];
        for (int i = 0; i < m; ++i) {
            a[i] = nextInt() - 1;
        }
        int[] pos = new int[n];
        Arrays.fill(pos, -1);
        pos[a[0]] = 0;
        int sum = 0;

        int[] cur = new int[n];
        cur[0] = a[0];
        int e = 1;
        for (int i = 1; i < m; ++i) {
            if (pos[a[i]] < 0) {
                pos[a[i]] = e;
                ++e;
            }

            for (int j = 0; j < pos[a[i]]; ++j) {
                sum += w[cur[j]];
            }
            for (int j = pos[a[i]]; j > 0; j--) {
                cur[j] = cur[j - 1];
                pos[cur[j]] = j;
            }
            cur[0] = a[i];
            pos[a[i]] = 0;

        }

        out.println(sum);
    }
}
