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;
inline void read_string_to_vector(vector<string> &vec) {
  string str;
  getline(cin, str);
  vec.push_back(str);
}
template <typename T>
inline void read_digit_to_vector(vector<T> &vec) {
  T t;
  cin >> t;
  vec.push_back(t);
}
long long n, m;
long long w[501];
long long b[1001];
long long books[501];
long long weight;
int main() {
  ios::sync_with_stdio(false);
  cin >> n >> m;
  for (register long long i = 0; i < n; ++i) {
    cin >> w[i];
  }
  for (register long long i = 0; i < m; ++i) cin >> b[i];
  books[0] = b[m - 1];
  long long k = 0;
  for (register long long i = m - 2; i >= 0 && k < (n - 1); --i) {
    if (b[i] != books[k]) {
      books[++k] = b[i];
    }
  }
  for (register long long i = 0; i < m; ++i) {
    long long bk = b[i];
    long long j = 0;
    while (true) {
      if (books[j] == bk) break;
      weight += w[books[j++] - 1];
    }
    while (j) {
      books[j] = books[j - 1];
      --j;
    }
    books[0] = bk;
  }
  cout << weight << "\n";
  return 0;
}
