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.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Arrays;
import java.util.Deque;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Scanner;
import java.util.stream.IntStream;

public class Main {

  public static void main(String[] args) throws IOException {
    InputScanner scanner = new InputScanner();
    while (scanner.hasNext()) {
      int n = scanner.nextInt();
      int m = scanner.nextInt();
      int[] weights = scanner.nextInts(n);
      int[] order = scanner.nextInts(m);
      boolean[] visited = new boolean[n];
      Arrays.fill(visited, false);
      Deque<Integer> currentOrder = new LinkedList<>();
      IntStream.range(0, m).forEach((e) -> {
        order[e]--;
        if (!visited[order[e]]) {
          visited[order[e]] = true;
          currentOrder.add(order[e]);
        }
      });
      long sum = 0;
      for (int i = 0; i < m; i++) {
        int p = order[i];
        for (Iterator<Integer> iter = currentOrder.iterator(); iter.hasNext();) {
          int e = iter.next();
          if (e == p) {
            iter.remove();
            break;
          } else {
            sum += weights[e];
          }
        }
        currentOrder.addFirst(p);
      }
      System.out.println(sum);
    }
  }
}

class InputScanner {
  private final Scanner scanner;

  public InputScanner() {
    this(System.in);
  }

  public InputScanner(String file) throws FileNotFoundException {
    this(new File(file));
  }

  public InputScanner(File file) throws FileNotFoundException {
    this(new FileInputStream(file));
  }

  public InputScanner(InputStream inputStream) {
    scanner = new Scanner(new BufferedInputStream(inputStream));
  }

  public boolean hasNext() {
    return scanner.hasNext();
  }

  public int nextInt() {
    return scanner.nextInt();
  }

  public int[] nextInts(int n) {
    int[] input = new int[n];
    for (int i = 0; i < n; i++) {
      input[i] = nextInt();
    }
    return input;
  }

  public String next() {
    return scanner.next();
  }

  @Override
  protected void finalize() throws Throwable {
    scanner.close();
    super.finalize();
  }
}