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 {
	
	static int[] order;
	static int[] w;
	static int min;
	
	public static void main(String[] args) throws Exception {
		BufferedReader f = new BufferedReader(new InputStreamReader(System.in));
		Scanner s = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		
		String[] split = f.readLine().split("\\s+");
		int n = Integer.parseInt(split[0]), m = Integer.parseInt(split[1]);
		w = new int[n+1];
		split = f.readLine().split("\\s+");
		for(int i = 1; i <= n; i++) {
			w[i] = Integer.parseInt(split[i-1]);
		}
		split = f.readLine().split("\\s+");
		order = new int[m];
		for(int i = 0; i < m; i++) order[i] = Integer.parseInt(split[i]);
		
		boolean[] used = new boolean[n+1];
		ArrayList<Integer> a = new ArrayList<>();
		for(int i = 0; i < order.length; i++) {
			if(!used[order[i]]) {
				used[order[i]] = true;
				a.add(order[i]);
			}
		}
		for(int i = 1; i <= n; i++) {
			if(!used[i]) {
				a.add(i);
			}
		}
		System.out.println(solve(a, order, w));
	}
	
	static void perm(boolean[] used, int at, int[] a) {
		if(at == a.length) {
			ArrayList<Integer> use = new ArrayList<>();
			for(Integer i : a) use.add(i);
			min = Math.min(min, solve(use, order, w));
			return;
		} else {
			for(int i = 0; i < a.length; i++) {
				if(!used[i]) {
					used[i] = true;
					a[at] = i+1;
					perm(used, at+1, a);
					used[i] = false;
				}
			}
		}
	}
	
	static int solve(ArrayList<Integer> a, int[] order, int[] w) {
		int res = 0;
		for(int i = 0; i < order.length; i++) {
			int idx = find(order[i], a);
			int add = 0;
			for(Integer j : a) {
				if(j == order[i]) break;
				add += w[j];
			}
			res += add;
			a.remove(idx);
			a.add(0, order[i]);
		}
		
		return res;
	}
	
	static int find(int num, ArrayList<Integer> a) {
		int count = 0;
		for(Integer i : a) {
			if(i == num) return count;
			count++;
		}
		return -1;
	}
}