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.math.*;
import java.util.*;


public class SolutionC {
    public static void main(String[] args){
        new SolutionC().run();
    }
    int n, m;
    int w[];
    int b[];
    int d[];
    int pos[];
    int used[];
    void solve(){
        n = in.nextInt();
        m = in.nextInt();
        w = in.nextArray(n);
        b = in.nextArray(m);
        d = new int[n];
        used = new int[n];
        pos = new int[n];
        
        for(int i = 0; i < m ;i++) b[i]--;
        int cur = n-1;
        long ans = 0;
        for(int i = 0; i < m; i++){
            if(used[b[i]] == 0){
                pos[b[i]] = cur;
                d[cur] = b[i];
                used[b[i]]=1;
                cur--;
            }
            int x = pos[b[i]];
            for(int j = x + 1; j < n; j++){
                int t = d[j];
                ans += w[d[j]];
                d[j] = d[j-1];
                d[j-1] = t;
                pos[d[j]] = j;
                pos[d[j-1]] = j-1;
            }
        }
        
        out.println(ans);
    }
    PrintWriter out;
    FastScanner in;
    public void run(){
        in = new FastScanner(System.in);
        out = new PrintWriter(System.out);
        solve();
        out.close();
    }
    
    class FastScanner{
        BufferedReader bf;
        StringTokenizer st;
        public FastScanner(InputStream is){
            bf = new BufferedReader(new InputStreamReader(is));
        }
        String next(){
            while(st == null || !st.hasMoreTokens()){
                try{
                    st = new StringTokenizer(bf.readLine());
                }
                catch(Exception ex){
                    ex.printStackTrace();
                }
            }
            return st.nextToken();
        }
        int nextInt(){
            return Integer.parseInt(next());
        }
        long nextLong(){
            return Long.parseLong(next());
        }
        double nextDouble(){
            return Double.parseDouble(next());
        }
        float nextFloat(){
            return Float.parseFloat(next());
        }
        BigInteger nextBigInteger(){
            return new BigInteger(next());
        }
        BigDecimal nextBigDecimal(){
            return new BigDecimal(next());
        }   
        int[] nextArray(int n){
            int x[] = new int[n];
            for(int i = 0; i < n; i++){
                x[i] = Integer.parseInt(next());
            }
            return x;
        }
    }
}
