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.math.BigInteger;
import java.util.*;

public class Solution {
  BufferedReader reader;

  int nextInt() throws IOException {
    tokenizer.nextToken();
    return (int) tokenizer.nval;
  }

  String next() throws IOException {
    tokenizer.nextToken();
    return tokenizer.sval;
  }

  StreamTokenizer tokenizer;
  Scanner in;

  void run() throws IOException {
    in = new Scanner(System.in);
    //    in = new Scanner(new File("input.txt"));
    PrintWriter out = new PrintWriter(System.out);
    reader = new BufferedReader(new InputStreamReader(System.in));
    //    reader = new BufferedReader(new FileReader(new File("input.txt")));
    tokenizer = new StreamTokenizer(reader);
    solve();
    in.close();
    reader.close();
    out.close();

  }


  int[] readAr(int n) throws IOException {
    int[] res = new int[n];
    String[] s = reader.readLine().split(" ");
    for (int i = 0; i < n; i++) res[i] = Integer.parseInt(s[i]);
    return res;
  }


  boolean[][] canSwap;
  int n;
  boolean[] visited;


  int solve(int[] w, int[] perm, int[] read) {
    int res = 0;
    int n = w.length;

    for (int r : read) {
      int where = -1;
      for (int j = 0; j < n; j++) if (perm[j] == r - 1) where = j;
      for (int i = 0; i < where; i++) {
        res += w[perm[i]];
      }
      int x = perm[where];
      for (int i = where; i > 0; i--) {
        perm[i] = perm[i - 1];
      }
      perm[0] = x;
    }
    return res;
  }

  void dfs(int v, List<Integer> comp) {
    comp.add(v);
    visited[v] = true;
    for (int i = 0; i < n; i++) {
      if (canSwap[v][i] && !visited[i]) {
        dfs(i, comp);
      }
    }
  }

  private void solve() throws IOException {
    int n = nextInt();
    int m = nextInt();
    int[] w = new int[n];
    for (int i = 0; i < n; i++) w[i] = nextInt();
    int[] read = new int[m];
    boolean[] used = new boolean[n];
    int[] perm = new int[n];
    int p = 0;
    for (int i = 0; i < m; i++) read[i] = nextInt();
    for (int r : read) {
      if (!used[r - 1]) {
        perm[p++] = r - 1;
        used[r - 1] = true;
      }
    }

    for (int i = 0; i < n; i++) {
      if (!used[i]) perm[p++] = i;
    }
    System.out.println(solve(w, perm, read));
  }

  private boolean less(int[] a, int[] b) {
    int i = 0;
    while (i < a.length && a[i] == b[i]) i++;
    if (i == a.length) return false;
    return a[i] < b[i];
  }

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

}