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

#include <bits/stdc++.h>
using namespace std;
#pragma comment(linker, "/STACK:102400000,102400000")
const int MAXN = 302020;
const int MAXM = 1602020;
const int INF = 0x3f3f3f3f;
const int mod = 1000000007;
const double eps = 1e-4;
int a[1330], w[1200], st[1200], vis[1200];
int main() {
  int n, m, num = 0, sum = 0;
  cin >> n >> m;
  memset(vis, 0, sizeof(vis));
  for (int i = 1; i <= n; i++) scanf("%d", &w[i]);
  for (int j = 1; j <= m; j++) scanf("%d", &a[j]);
  for (int i = 1; i <= n; i++) {
    if (vis[a[i]] == 0) {
      st[num++] = a[i];
      vis[a[i]] = 1;
    }
  }
  for (int i = 1; i <= m; i++) {
    int x;
    for (int j = 0; j < num; j++) {
      if (a[i] == st[j]) {
        x = j;
        break;
      }
      sum += w[st[j]];
    }
    for (int j = 1; j <= x; j++) {
      vis[j] = st[j - 1];
    }
    vis[0] = st[x];
    for (int j = 0; j <= x; j++) st[j] = vis[j];
  }
  printf("%d\n", sum);
  return 0;
}
