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

/*
PROG: c
LANG: JAVA
*/
import java.util.*;
import java.io.*;

public class c {

  private void solve() throws IOException {
    int n = nextInt(), m = nextInt();
    int[] w = new int[n];
    int[] d = new int[m];
    for(int i = 0; i < n; ++i)
      w[i] = nextInt();

    List<Integer> v = new ArrayList<>();
    int r = 0;
    for(int i = 0; i < m; ++i) {
      int j = nextInt(); 
      if(v.indexOf(j) > -1) {
        v.remove(v.indexOf(j));
      } 
      v.add(0, j); 
      d[i] = j;
    }
    for(int i = 0; i < m; ++i) {
      int j = d[i], k = v.indexOf(j);
      for(int l = 0; l < k; ++l)
        r += w[v.get(l) - 1];
      v.add(0, v.remove(k));
    }
    System.out.println(r);
  }

  static void debug(Object...o) {
    System.err.println(Arrays.deepToString(o));
  }

  BufferedReader br;
  StringTokenizer st;
  PrintWriter out = new PrintWriter(System.out);

  String next() throws IOException {
    while (st == null || !st.hasMoreTokens()) {
      st = new StringTokenizer(br.readLine());
    }
    return st.nextToken();
  }

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

  double nextDouble() throws IOException {
    return Double.parseDouble(next());
  }

  long nextLong() throws IOException {
    return Long.parseLong(next());
  }

  private void run() throws IOException {
    //br = new BufferedReader(new FileReader("c.in"));
    br = new BufferedReader(new InputStreamReader(System.in));
    solve();
    out.close();
  }

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