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;
template <typename T>
T Abs(T first) {
  return (first < 0 ? -first : first);
}
template <typename T>
T Sqr(T first) {
  return (first * first);
}
string plural(string s) {
  return (int((s).size()) && s[int((s).size()) - 1] == 'x' ? s + "en"
                                                           : s + "s");
}
const int INF = (int)1e9;
const long double EPS = 1e-9;
const long double PI = acos(-1.0);
bool Read(int &first) {
  char c, r = 0, n = 0;
  first = 0;
  for (;;) {
    c = getchar();
    if ((c < 0) && (!r)) return (0);
    if ((c == '-') && (!r))
      n = 1;
    else if ((c >= '0') && (c <= '9'))
      first = first * 10 + c - '0', r = 1;
    else if (r)
      break;
  }
  if (n) first = -first;
  return (1);
}
bool ReadLL(long long &first) {
  char c, r = 0, n = 0;
  first = 0;
  for (;;) {
    c = getchar();
    if ((c < 0) && (!r)) return (0);
    if ((c == '-') && (!r))
      n = 1;
    else if ((c >= '0') && (c <= '9'))
      first = first * 10 + c - '0', r = 1;
    else if (r)
      break;
  }
  if (n) first = -first;
  return (1);
}
int main() {
  if (0) freopen("in.txt", "r", stdin);
  int N, M;
  int i, j, k, c;
  static int V[1005], ord[1005], ind[1005];
  static pair<int, int> P[1005];
  stack<int> S, S2;
  Read(N), Read(M);
  for (i = 0; i < N; i++) Read(V[i]);
  memset(ind, 60, sizeof(ind));
  for (i = 0; i < M; i++) {
    Read(ord[i]), ord[i]--;
    ind[ord[i]] = min(ind[ord[i]], i);
  }
  for (i = 0; i < N; i++) P[i] = make_pair(ind[i], i);
  sort(P, P + N);
  for (i = (N)-1; i >= 0; i--) S.push(P[i].second);
  long long ans = 0;
  for (i = 0; i < M; i++) {
    j = ord[i];
    while (S.top() != j) ans += V[S.top()], S2.push(S.top()), S.pop();
    S.pop();
    while (!S2.empty()) S.push(S2.top()), S2.pop();
    S.push(j);
  }
  cout << ans << endl;
  return (0);
}
