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.util.*;
import java.io.*;

public class Main {

	BufferedReader in;
	StringTokenizer str = null;
	PrintWriter out;
	
	private String next() throws Exception{
		while (str == null || !str.hasMoreElements())
			str = new StringTokenizer(in.readLine());
		return str.nextToken();
	}
	
	private int nextInt() throws Exception{
		return Integer.parseInt(next());
	}
	
	private long nextLong() throws Exception{
		return Long.parseLong(next());
	}
	
	private double nextDouble() throws Exception{
		return Double.parseDouble(next());
	}
	
	public void run() throws Exception{
		in =  new BufferedReader(new InputStreamReader(System.in));
		out = new PrintWriter(System.out);
		int n = nextInt(), m = nextInt();
		int []w = new int[n];
		for(int i = 0; i < n; ++i) w[i] = nextInt();
		int []a = new int[m];
		for(int i = 0; i < m; ++i) a[i] = nextInt() - 1;

		List<Integer> list = new ArrayList<Integer>();
		boolean []used = new boolean[n];
		for(int i = 0; i < m; ++i) {
			if (used[a[i]]) continue;
			used[a[i]] = true;
			list.add(a[i]);
		}

		// System.out.println(list);

		int ret = 0;
		for(int i = 0; i < m; ++i) {
			int x = a[i], sum = 0;
			for(int j = 0; j < list.size(); ++j) {
				if (list.get(j) == x) {
					list.remove(j);
					list.add(0, x);
					break;
				}
				sum += w[list.get(j)];
			}
			ret += sum;
		}

		out.println(ret);
		out.close();
	}
		
	public static void main(String[] args) throws Exception{
		new Main().run();
	}
}
