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

/* package whatever; // don't place package name! */

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

/* Name of the class has to be "Main" only if the class is public. */
public class Ideone
{
    public static void main (String[] args) throws java.lang.Exception
    {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();
        int w[] = new int[n];
        int b[] = new int[m];
        for(int i = 0;i<n;i++){
            w[i]=sc.nextInt();
        }
        for(int i = 0;i<m;i++){
            b[i]=sc.nextInt()-1;
        }
        ArrayList<Integer> sa = new ArrayList<Integer>();
        boolean taken[] = new boolean[n];
        for(int i = 0;i<n;i++){
            taken[i]=false;
        }
        for(int i = 0;i<m;i++){
            if(!taken[b[i]]){
                taken[b[i]]=true;
                sa.add(b[i]);
            }
        }
        int answer = 0;
        for(int i = 0;i<m;i++){
            int x = -1;
            for(int j=0;j<sa.size();j++){
                if(sa.get(j)!=b[i]){
                    answer+=w[sa.get(j)];
                }
                else{
                    x=j;
                    break;
                }
            }
            sa.remove(x);
            sa.add(0,b[i]);
        }
        System.out.println(answer);
    }
}