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.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.io.PrintStream;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import java.util.StringTokenizer;

import org.omg.CORBA.PUBLIC_MEMBER;

/*
public class _500C {

}

 */

class node implements Comparable<node>
{
	public int n;
	public int w;
	public int m;
	
	public int compareTo(node o) 
	{
		return (this.m - o.m);
	}
}

public class _500C {
	private static PrintWriter printWriter;

	public void solve() throws FileNotFoundException {
		InputStream inputStream = System.in;

		InputHelper inputHelper = new InputHelper(inputStream);

		PrintStream out = System.out;

		//actual solution

		int n = inputHelper.readInteger();
		int m = inputHelper.readInteger();
		
		int[] ma = new int[m];
		
		node[] nodes = new node[n];
		for(int i = 0; i < n; i++)
		{
			nodes[i] = new node();
			
			nodes[i].n = i + 1;
			nodes[i].w = inputHelper.readInteger();
			nodes[i].m = -1;
		}
		
		for(int i = 0; i < m; i++)
		{
			int mv = inputHelper.readInteger();
			
			ma[i] = mv;
			
			if(nodes[mv - 1].m == -1)
			{
				nodes[mv - 1].m = i;
			}
		}
		
		Arrays.sort(nodes);
		
		int lw = 0;
		for(int i = 0; i < m; i++)
		{
			int j;
			for(j = 0;; j++)
			{
				if(nodes[j].n != ma[i])
				{
					lw += nodes[j].w;
				}
				else
					break;
			}
			
			for(int k = 0; k < j; k++)
			{
				swap(nodes, k, j);
			}
		}
		
		System.out.println(lw);
		//end here

	}

	private void swap(node[] nodes, int k, int j) {
		node t = nodes[k];
		
		nodes[k] = nodes[j];
		nodes[j] = t;
	}

	public static void main(String[] args) throws FileNotFoundException {
		(new _500C()).solve();
	}

	class InputHelper {
		StringTokenizer tokenizer = null;
		private BufferedReader bufferedReader;

		public InputHelper(InputStream inputStream) {
			InputStreamReader inputStreamReader = new InputStreamReader(
					inputStream);
			bufferedReader = new BufferedReader(inputStreamReader, 16384);
		}

		public String read() {
			while (tokenizer == null || !tokenizer.hasMoreTokens()) {
				try {
					String line = bufferedReader.readLine();
					if (line == null) {
						return null;
					}
					tokenizer = new StringTokenizer(line);
				} catch (IOException e) {
					e.printStackTrace();
				}
			}

			return tokenizer.nextToken();
		}

		public Integer readInteger() {
			return Integer.parseInt(read());
		}

		public Long readLong() {
			return Long.parseLong(read());
		}
	}
}