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>
int n, m;
int w[501];
int b[1001];
int next[501];
int prev[501];
int head;
int sum = 0;
void order() {
  int last;
  int select[501] = {0};
  head = b[1];
  last = head;
  select[b[1]] = 1;
  prev[head] = 0;
  for (int i = 2; i <= m; i++) {
    if (select[b[i]] == 0) {
      select[b[i]] = 1;
      next[last] = b[i];
      prev[b[i]] = last;
      last = b[i];
    }
  }
  int u = 10;
  return;
}
int get_weight(int i) {
  int sum = 0;
  i = prev[i];
  while (i != head) {
    sum += w[i];
    i = prev[i];
  }
  sum += w[head];
  return sum;
}
void move() {
  for (int i = 1; i <= m; i++) {
    if (head == b[i]) {
      continue;
    }
    sum += get_weight(b[i]);
    next[prev[b[i]]] = next[b[i]];
    prev[next[b[i]]] = prev[b[i]];
    next[b[i]] = head;
    prev[head] = b[i];
    head = b[i];
    prev[b[i]] = 0;
  }
}
void solve() {
  order();
  move();
  return;
}
int main() {
  scanf("%d %d\n", &n, &m);
  for (int i = 1; i <= n; i++) {
    scanf("%d ", w + i);
  }
  for (int i = 1; i <= m; i++) {
    scanf("%d ", b + i);
  }
  solve();
  printf("%d", sum);
  return 0;
}
