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;
const int N = 1005;
struct nodo {
  int sum;
};
int n, m;
bool used[N];
int w[N];
int s[2 * N];
vector<int> libros;
nodo st[8 * N];
nodo NIL;
nodo merge(nodo a, nodo b) {
  nodo q;
  q.sum = a.sum + b.sum;
  return q;
}
void build(int pos = 1, int l = 0, int r = N + n - 1) {
  if (l == r) {
    st[pos].sum = w[s[l]];
    return;
  }
  int mi = (l + r) / 2;
  build(2 * pos, l, mi);
  build(2 * pos + 1, mi + 1, r);
  st[pos] = merge(st[2 * pos], st[2 * pos + 1]);
}
void update(int x, int y, int pos = 1, int l = 0, int r = N + n - 1) {
  if (l == r) {
    st[pos].sum = y;
    return;
  }
  int mi = (l + r) / 2;
  if (l <= x && x <= mi)
    update(x, y, 2 * pos, l, mi);
  else
    update(x, y, 2 * pos + 1, mi + 1, r);
  st[pos] = merge(st[2 * pos], st[2 * pos + 1]);
}
nodo queryn(int x, int y, int pos = 1, int l = 0, int r = N + n - 1) {
  if (y < l || r < x) return NIL;
  if (x <= l && r <= y) return st[pos];
  int mi = (l + r) / 2;
  nodo L = queryn(x, y, 2 * pos, l, mi);
  nodo R = queryn(x, y, 2 * pos + 1, mi + 1, r);
  return merge(L, R);
}
int query(int x, int y) {
  nodo ans = queryn(x, y);
  return ans.sum;
}
int solve() {
  int c = 0;
  for (int i = 0; i < libros.size(); i++) {
    for (int j = N - i; j < N + n; j++) {
      if (s[j] == libros[i]) {
        c += query(0, j - 1);
        s[N - i - 1] = s[j];
        s[j] = 0;
        update(j, 0);
        update(N - i - 1, w[libros[i]]);
      }
    }
  }
  return c;
}
int main() {
  NIL.sum = 0;
  int b;
  int pos = 0;
  cin >> n >> m;
  for (int i = 1; i <= n; i++) cin >> w[i];
  while (m--) {
    cin >> b;
    libros.push_back(b);
    if (!used[b]) {
      s[N + pos++] = b;
      used[b] = true;
    }
  }
  for (int i = pos; i < n; i++) {
    bool can = false;
    for (int j = 1; j <= n && !can; j++) {
      if (!used[j]) {
        s[N + i] = j;
        used[j] = true;
        can = true;
      }
    }
  }
  build();
  int ans = solve();
  cout << ans << endl;
  return 0;
}
