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.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.LinkedList;
import java.util.StringTokenizer;

/**
 * Built using CHelper plug-in Actual solution is at the top
 */
public class Main {
	public static void main(String[] args) {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		TaskD solver = new TaskD();
		solver.solve(1, in, out);
		out.close();
	}
}

class TaskD {
	static final long MODULO = (int) (1e9 + 7);

	public void solve(int testNumber, InputReader in, PrintWriter out) {

		int n = in.nextInt();
		int m = in.nextInt();
		
		int[] a = new int[n];
		int[] c = new int[n];
		int[] b = new int[m];
		LinkedList<Integer> l = new LinkedList<Integer>();
		int[] p = new int[n];
		
		for (int i = 0; i < n; i++) {
			a[i] = in.nextInt();
			p[i] = -1;
		}
		int t;
		for (int i = 0; i < m; i++){
			t = in.nextInt()-1;
			b[i] = t;
			c[t] = 1;
		}
		int count = 0;
		for (int i = 0; i < m; i++){
			if (c[b[i]] == 1){
				l.add(b[i]);
				c[b[i]] = 0;
			}
		}
		long sum = 0L;
		//System.out.println(l);
		for (int i = 0; i < m; i++){
			count = 0;
			for (Integer h : l) {
				if (h == b[i]) {
					break;
				}
				count++;
				sum+=a[h];
			}
			l.remove(count);
			l.add(0, b[i]);
			
		}
		
		
		//for (int i = 0; i < n; i++) {
				System.out.print(sum);
		//}
		
		

	}
}

class Pair implements Comparable<Pair> {
	public int v;

	public Pair(int a) {
		v = a;
	}

	@Override
	public int compareTo(Pair arg0) {
		// TODO Auto-generated method stub
		return this.v - arg0.v;
	}

}

class InputReader {
	public BufferedReader reader;
	public StringTokenizer tokenizer;

	public InputReader(InputStream stream) {
		reader = new BufferedReader(new InputStreamReader(stream), 32768);
		tokenizer = null;
	}

	public String next() {
		while (tokenizer == null || !tokenizer.hasMoreTokens()) {
			try {
				tokenizer = new StringTokenizer(reader.readLine());
			} catch (IOException e) {
				throw new RuntimeException(e);
			}
		}
		return tokenizer.nextToken();
	}

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

}