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 double PI = 2 * acos(0.0);
const double eps = 1e-9;
template <class T>
T jog(T a, T b) {
  return a + b;
}
template <class T>
T bog(T a, T b) {
  return a - b;
}
template <class T>
T gon(T a, T b) {
  return a * b;
}
template <class T>
T sq(T x) {
  return x * x;
}
template <class T>
T gcd(T a, T b) {
  return b == 0 ? a : gcd(b, a % b);
}
template <class T>
T lcm(T a, T b) {
  return (a / gcd(a, b)) * b;
}
template <class T>
T power(T a, T p) {
  int res = 1, x = a;
  while (p) {
    if (p & 1) res = res * x;
    x = x * x;
    p >>= 1;
  }
  return res;
}
template <class T>
T cordinatlenth(T a, T b, T c, T d) {
  return sqrt(sq(a - c) + sq(b - d));
}
template <class T>
string toString(T n) {
  ostringstream oss;
  oss << n;
  oss.flush();
  return oss.str();
}
int toInt(string s) {
  int r = 0;
  istringstream sin(s);
  sin >> r;
  return r;
}
long long bigmod(long long a, long long p, long long mod) {
  long long res = 1, x = a;
  while (p) {
    if (p & 1) res = (res * x) % mod;
    x = (x * x) % mod;
    p >>= 1;
  }
  return res;
}
int diraction1[] = {-1, 0, 0, 1, 1, -1, -1, 1};
int diraction2[] = {0, -1, 1, 0, 1, -1, 1, -1};
int horsed1[] = {-2, -2, -1, 1, 2, 2, 1, -1};
int horsed2[] = {1, -1, -2, -2, -1, 1, 2, 2};
void input();
int n, m, w[510], b[1010], st[1010];
long long ans;
int main() {
  input();
  return 0;
}
void input() {
  scanf("%d %d", &n, &m);
  ans = 0;
  for (int i = 1; i <= n; i++) scanf("%d", &w[i]);
  for (int i = 0; i < m; i++) scanf("%d", &b[i]);
  memset(st, -1, sizeof(st));
  int ind = 0;
  st[ind++] = b[0];
  for (int i = 1; i < m; i++) {
    int sum = 0, flag = 1;
    for (int j = 0; j < ind; j++) {
      if (st[j] == b[i]) {
        for (int k = j; k > 0; k--) st[k] = st[k - 1];
        st[0] = b[j];
        flag = 0;
        break;
      }
      ans += w[st[j]];
    }
    if (flag) {
      ind++;
      for (int j = ind; j > 0; j--) st[j] = st[j - 1];
      st[0] = b[i];
    }
  }
  cout << ans << endl;
}
