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.io.PrintWriter;
import java.util.Arrays;
import java.util.Comparator;
import java.util.StringTokenizer;

public class Main {

	private void solve() throws IOException {
		solve(ni());
		out.println();
		out.close();
	}

	private void solve(int n) throws IOException {
		int m = ni();
		int last[] = new int[n];
		Arrays.fill(last, -1);
		int w[] = nia(n);
		int ans = 0;
		for (int i = 0; i < m; i++) {
			int c = ni() - 1;
			for (int j = 0; j < n; j++)
				if (last[j] > last[c])
					ans += w[j];
			last[c] = i;
		}

		out.println(ans);
	}

	static BufferedReader in;
	static PrintWriter out;
	static StringTokenizer tok;

	private long[][] na(int n) throws IOException {
		long[][] a = new long[n][4];
		for (int i = 0; i < n; i++) {
			a[i][0] = nl();
			a[i][1] = nl();
			a[i][2] = nl();
		}
		return a;
	}

	String ns() throws IOException {
		while (!tok.hasMoreTokens()) {
			tok = new StringTokenizer(in.readLine(), " ");
		}
		return tok.nextToken();
	}

	int ni() throws IOException {
		return Integer.parseInt(ns());
	}

	long nl() throws IOException {
		return Long.parseLong(ns());
	}

	double nd() throws IOException {
		return Double.parseDouble(ns());
	}

	String[] nsa(int n) throws IOException {
		String[] res = new String[n];
		for (int i = 0; i < n; i++) {
			res[i] = ns();
		}
		return res;
	}

	int[] nia(int n) throws IOException {
		int[] res = new int[n];
		for (int i = 0; i < n; i++) {
			res[i] = ni();
		}
		return res;
	}

	long[] nla(int n) throws IOException {
		long[] res = new long[n];
		for (int i = 0; i < n; i++) {
			res[i] = nl();
		}
		return res;
	}

	public static void main(String[] args) throws IOException {
		in = new BufferedReader(new InputStreamReader(System.in));
		out = new PrintWriter(System.out);
		tok = new StringTokenizer("");
		Main main = new Main();
		main.solve();
		out.close();
	}
}