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.*;

public class CF_GoodBye2014_C {

    static int INFINITY = 2000000000;

    public static void main(String[] args) throws IOException {
        br = new BufferedReader(new InputStreamReader(System.in));
        out = new PrintWriter(System.out);
        sc = new StringTokenizer("");
        sb = new StringBuilder();

        int n = nxtInt();
        int m = nxtInt();

        int books[] = new int[n];
        books = nxtIntArr(n);
        int days[] = new int[m];
        for (int i = 0; i < m; i++) {
            days[i] = nxtInt() - 1;
        }

        int stack[] = new int[n];
        boolean taken[] = new boolean[n];

        int j = 0;
        for (int i = 0; i < m; i++) {
            if (!taken[days[i]]) {
                stack[j] = days[i];
                j++;
            }
            taken[days[i]] = true;
        }
//
//      for (int i = 0; i < n; i++) {
//          System.out.println(stack[i]);
//      }

        long weight = 0;
        for (int i = 0; i < m; i++) {
            int book = stack[0];
            j = 0;
            while (book != days[i]) {
                weight += books[book];
                int temp=book;
                book = stack[j + 1];
                stack[j + 1] = temp;
                j++;
            }
            stack[0] = book;
        }
        System.out.println(weight);

    }// end Main.

    static BufferedReader br;
    static StringTokenizer sc;
    static PrintWriter out;
    static StringBuilder sb;

    static String nxtTok() throws IOException {
        while (!sc.hasMoreTokens()) {
            String s = br.readLine();
            if (s == null)
                return null;
            sc = new StringTokenizer(s.trim());
        }
        return sc.nextToken();
    }

    static int nxtInt() throws IOException {
        return Integer.parseInt(nxtTok());
    }

    static long nxtLng() throws IOException {
        return Long.parseLong(nxtTok());
    }

    static double nxtDbl() throws IOException {
        return Double.parseDouble(nxtTok());
    }

    static int[] nxtIntArr(int n) throws IOException {
        int[] a = new int[n];
        for (int i = 0; i < n; i++)
            a[i] = nxtInt();
        return a;
    }

    static long[] nxtLngArr(int n) throws IOException {
        long[] a = new long[n];
        for (int i = 0; i < n; i++)
            a[i] = nxtLng();
        return a;
    }

    static char[] nxtCharArr() throws IOException {
        return nxtTok().toCharArray();
    }

}// end class
