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;
vector<pair<int, int> > v;
int x[1500], w[1500], c[1500], ans, l, n, m, fposs[1500];
vector<int> a, st;
char ch;
bool cmp(pair<int, int> a, pair<int, int> b) {
  if (a.first < b.first) return true;
  if (fposs[a.second] > fposs[b.second]) return true;
  return false;
}
int main() {
  cin.tie(NULL);
  ios_base::sync_with_stdio(false);
  cin >> n >> m;
  for (int i = 1; i <= n; i++) cin >> w[i];
  for (int i = 1; i <= m; i++) {
    cin >> x[i];
    c[x[i]]++;
    if (fposs[x[i]] == 0) fposs[x[i]] = i;
  }
  for (int i = 1; i <= n; i++) v.push_back(make_pair(c[i], i));
  sort(v.begin(), v.end(), cmp);
  for (int i = 0; i < n; i++) a.push_back(v[i].second);
  for (int i = 1; i <= m; i++) {
    l = n - 1;
    st.clear();
    while (a[l] != x[i]) {
      ans += w[a[l]];
      st.push_back(a[l]);
      l--;
      a.pop_back();
    }
    a.pop_back();
    for (int j = st.size() - 1; j >= 0; j--) {
      a.push_back(st[j]);
      st.pop_back();
    }
    a.push_back(x[i]);
  }
  cout << ans;
}
