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.io.PrintWriter;
import java.util.ArrayList;
import java.util.StringTokenizer;

/**
 * Created by Greg on 2015/9/16.
 */
public class NewYearBookReading_500C {
    private static void run() {
        br = new BufferedReader(new InputStreamReader(System.in));
        out = new PrintWriter(System.out);

        int n = nextInt();
        int m = nextInt();
        int[] w = new int[n+1];
        int[] t = new int[m+1];
        for (int i = 1; i <= n; i++) {
            w[i] = nextInt();
        }
        int sumW = 0;
        ArrayList<Integer> s = new ArrayList<Integer>();
        for (int i = 1; i <= m; i++) {
            int b = nextInt();
            int j = 0;
            for ( ; j < s.size(); j++) {
                int b1 = s.get(j);
                if (b1 != b) {
                    sumW += w[b1];
                } else {
                    s.remove(j);
                    s.add(0, b1);
                    break;
                }
            }
            if (j==s.size()) {
                s.add(0,b);
            }
        }
        out.println(sumW);
        out.close();
    }

    private static StringTokenizer st;
    private static BufferedReader br;
    private static PrintWriter out;

    private static String next() {
        while (st == null || !st.hasMoreElements()) {
            String s;
            try {
                s = br.readLine();
            } catch (IOException e) {
                return null;
            }
            st = new StringTokenizer(s);
        }
        return st.nextToken();
    }

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

    private static long nextLong() {
        return Long.parseLong(next());
    }

    public static void main(String[] args) {
        run();
    }
}
