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 c1 {
	
	static class Pair implements Comparable<Pair>{
		int x;
		int y;
		
		Pair(int _x, int _y){
			x = _x;
			y = _y;
		}

		public int compareTo(Pair o) {
			if (this.x == o.x){
				return this.y - o.y;
			}
			else{
				return this.x - o.x;
			}
		}		
	}
	
	public static void main(String[] args) throws FileNotFoundException {
		Scanner in = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		int n = in.nextInt();
		int m = in.nextInt();
		int w[] = new int[n + 1];
		int b[] = new int[m + 1];
		for (int i = 0; i < n; i++) {
			w[i] = in.nextInt();
		}
		int f[] = new int[n + 1];
		Arrays.fill(f, -1);
		for (int i = 0; i < m; i++) {
			b[i] = in.nextInt();
			b[i]--;
			if (f[b[i]] == -1){
				f[b[i]] = i;
			}
		}
		Pair q[] = new Pair[n];
		for (int i = 0; i < n; i++) {
			if (f[i] == -1){
				q[i] = new Pair(n, i);
			}
			else{
				q[i] = new Pair(f[i], i);
			}
		}
		Arrays.sort(q);
		w[n] = 0;
		long ans = 0;
		ArrayList<Integer> st = new ArrayList<Integer>();
		for (int i = n - 1; i > -1; i--) {
			st.add(q[i].y);
		}
		for (int i = 0; i < m; i++) {
			long cur = 0;	
			for (int j = st.size() - 1; j > -1; j--) {
				if (st.get(j) == b[i]){
					st.remove(st.get(j));
					st.add(b[i]);
					break;
				}
				else{
					cur += w[st.get(j)];
				}
			}
			ans = (long) ans + cur;
		}
		out.print(ans);
		out.close();
	}
}
