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.*;
import java.util.*;

public class C{
	public static boolean DEBUG = true;
	
	public static void main(String[] args) throws Exception{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		PrintWriter pw = new PrintWriter(System.out);
		
		StringTokenizer st = getst(br);
		
		int n = nextInt(st);
		int m = nextInt(st);
		
		int[] weights = new int[n];
		boolean[] read = new boolean[n];
		
		st = getst(br);
		
		for(int i = 0; i < n; i++){
			weights[i] = nextInt(st);
		}
		
		st = getst(br);
		
		int sum = 0;
		long ans = 0;
		
		ArrayList<Integer> books = new ArrayList<Integer>();
		
		for(int i = 0; i < m; i++){
			int next = nextInt(st)-1;
			if(!read[next]){
				books.add(next);
				read[next] = true;
				ans += sum;
				sum += weights[next];
			} else {
				int s = 0;
				for(int j = books.size()-1; j >= 0; j--){
					if(books.get(j) == next){
						books.remove(j);
						ans += s;
						break;
					} else {
						ans += weights[books.get(j)];
					}
				}
				
				books.add(next);
			}
		}
		
		pw.println(ans);
		
		br.close();
		pw.close();
	}
	
	public static void debug(Object o){
		if(DEBUG){
			System.out.println("~" + o);
		}
	}
	
	public static StringTokenizer getst(BufferedReader br) throws Exception{
		return new StringTokenizer(br.readLine(), " ");
	}
	
	public static int nextInt(BufferedReader br) throws Exception{
		return Integer.parseInt(br.readLine());
	}
	
	public static int nextInt(StringTokenizer st) throws Exception{
		return Integer.parseInt(st.nextToken());
	}
}