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;
struct node {
  int lis;
  struct node *link;
};
int n, m, i, j, sum, ans;
int readlist[1005], w[505], vis[505];
node *initial() {
  node *head, *p1, *p2;
  head = (node *)malloc(sizeof(node));
  head->link = NULL;
  head->lis = 0;
  p1 = head;
  for (int i = 1; i <= m; i++) {
    cin >> readlist[i];
    if (vis[readlist[i]] == 0) {
      p2 = (node *)malloc(sizeof(node));
      p2->lis = readlist[i];
      p2->link = NULL;
      p1->link = p2;
      p1 = p2;
      vis[readlist[i]] = 1;
    }
  }
  return (head);
}
void append(node *head, int v) {
  node *ptr;
  ptr = (node *)malloc(sizeof(node));
  ptr->lis = v;
  ptr->link = head->link;
  head->link = ptr;
}
void delet(node *pf) {
  node *ptr;
  ptr = pf->link;
  if (ptr != NULL) {
    pf->link = ptr->link;
    free(ptr);
  }
}
void search(node *head, int v) {
  node *ptr;
  ptr = (node *)malloc(sizeof(node));
  ptr = head;
  while (1) {
    sum += w[ptr->lis];
    if (ptr->link->lis == v) break;
    ptr = ptr->link;
  }
  delet(ptr);
  append(head, v);
}
void print(node *head) {
  node *ptr;
  ptr = (node *)malloc(sizeof(node));
  ptr = head->link;
  while (1) {
    cout << ptr->lis << " ";
    if (ptr->link == NULL) break;
    ptr = ptr->link;
  }
  cout << endl;
}
int main() {
  while (cin >> n >> m) {
    memset(w, 0, sizeof(w));
    memset(readlist, 0, sizeof(readlist));
    memset(vis, 0, sizeof(vis));
    sum = 0;
    for (i = 1; i <= n; i++) cin >> w[i];
    node *head;
    head = initial();
    for (i = 1; i <= m; i++) {
      search(head, readlist[i]);
    }
    cout << sum << endl;
  }
  return 0;
}
