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.InputStreamReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.StringTokenizer;


public class C {
	
	static class Scanner{
		BufferedReader br=null;
		StringTokenizer tk=null;
		public Scanner(){
			br=new BufferedReader(new InputStreamReader(System.in));
		}
		public String next() throws IOException{
			while(tk==null || !tk.hasMoreTokens())
				tk=new StringTokenizer(br.readLine());
			return tk.nextToken();
		}
		public int nextInt() throws NumberFormatException, IOException{
			return Integer.valueOf(next());
		}
		public long nextLong() throws NumberFormatException, IOException{
			return Long.valueOf(next());
		}
		public double nextDouble() throws NumberFormatException, IOException{
			return Double.valueOf(next());
		}
	}
	
	static class Pair implements Comparable<Pair>{
		int id;
		int key;
		public Pair(int i, int k){
			id = i;
			key = k;
		}
		@Override
		public int compareTo(Pair o) {
			return this.key - o.key;
		}
	}
	
	static int N, M;
	static int[] W;
	static int[] B;
	static int global;
	
	static int contains(ArrayList<Pair> a, int id){
		for(int i = 0; i < a.size(); i++)
			if (a.get(i).id == id)
				return i;
		return -1;
	}
	
	public static void main(String args[]) throws NumberFormatException, IOException{
		Scanner sc = new Scanner();
		N = sc.nextInt();
		M = sc.nextInt();
		W = new int[N];
		for(int i = 0; i < N; i++)
			W[i] = sc.nextInt();
		B = new int[M];
		for(int i = 0; i < M; i++)
			B[i] = sc.nextInt() - 1;
		ArrayList<Pair> a = new ArrayList<Pair>();
		int lifted = 0;
		global = 0;
		for(int i = 0; i < M; i++){
			int cur = B[i];
			int idx = contains(a, cur);
			if (idx >= 0){
				for(int j = idx + 1; j < a.size(); j++)
					lifted += W[a.get(j).id];
				a.get(idx).key = global;
				global++;
				Collections.sort(a);
			}
			else{
				for(int j = 0; j < a.size(); j++)
					lifted += W[a.get(j).id];
				a.add(new Pair(cur, global));
				global++;
				Collections.sort(a);
			}
		}
		System.out.println(lifted);
	}

}
