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 gcd(T u, T v) {
  while (v != 0) {
    T r = u % v;
    u = v;
    v = r;
  }
  return u;
}
template <typename T>
T factorial(T n) {
  return (n == 1 || n == 0) ? 1 : factorial(n - 1) * n;
}
int n, m, a[100005], b[100005], c[100005], ans;
std::vector<int> v;
int main() {
  scanf("%d %d", &n, &m);
  for (int i = 0; i < n; ++i) scanf("%d", &a[i]);
  for (int i = 0; i < m; ++i) scanf("%d", &b[i]);
  for (int i = 0; i < m; ++i) {
    if (c[b[i] - 1] == 0) v.push_back(b[i]);
    c[b[i] - 1] = 1;
  }
  ans = 0;
  for (int i = 0; i < m; ++i) {
    for (int j = 0; j < v.size(); ++j) {
      if (v[j] != b[i])
        ans += a[v[j] - 1];
      else {
        for (int k = j; k > 0; --k) v[k] = v[k - 1];
        v[0] = b[i];
        break;
      }
    }
  }
  printf("%d\n", ans);
  return 0;
}
