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 <class T>
inline T BM(T p, T e, T M) {
  long long int ret = 1;
  for (; e > 0; e >>= 1) {
    if (e & 1) ret = (ret * p) % M;
    p = (p * p) % M;
  }
  return (T)ret;
}
template <class T>
inline T gcd(T a, T b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
template <class T>
inline T MDINV(T a, T M) {
  return BM(a, M - 2, M);
}
template <class T>
inline T PW(T p, T e) {
  long long int ret = 1;
  for (; e > 0; e >>= 1) {
    if (e & 1) ret = (ret * p);
    p = (p * p);
  }
  return (T)ret;
}
template <class T>
string NTS(T Number) {
  stringstream ss;
  ss << Number;
  return ss.str();
}
template <class T>
T stringtonumber(const string &Text) {
  istringstream ss(Text);
  T result;
  return ss >> result ? result : 0;
}
int main() {
  int n, m;
  scanf("%d%d", &n, &m);
  int a[n + 2];
  for (int i = 1; i <= n; i++) {
    scanf("%d", &a[i]);
  }
  int b[m + 2];
  for (int j = 1; j <= m; j++) {
    scanf("%d", &b[j]);
  }
  int c = 0;
  int d[n + 5];
  int g[n + 2];
  memset(g, 0, sizeof g);
  for (int k = m; k >= 1; k--) {
    int e = b[k];
    if (g[e] == 0) {
      d[++c] = e;
      g[e] = c;
    } else {
      int lm = g[e] - 1;
      for (int l = lm; l >= 1; l--) {
        d[l + 1] = d[l];
        g[d[l + 1]] = l + 1;
      }
      d[1] = e;
      g[e] = 1;
    }
  }
  int sum = 0;
  for (int i = 1; i <= m; i++) {
    int e = b[i];
    int sz = g[e];
    for (int l = sz - 1; l >= 1; l--) {
      sum += a[d[l]];
      d[l + 1] = d[l];
      g[d[l + 1]] = l + 1;
    }
    d[1] = e;
    g[e] = 1;
  }
  pair<char, int>(sum);
  return 0;
}
