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;
ifstream fin("frac1.in");
ofstream fout("frac1.out");
class compare : public std::binary_function<double, double, bool> {
 public:
  compare(double arg = 1e-7) : e(arg) {}
  bool operator()(const double &left, const double &right) const {
    return (abs(left - right) > e) && (left < right);
  }
  double e;
};
inline int d_compare(double x, double y) {
  return (fabs(x - y) <= 1e-7) ? 0 : (x > y) ? 1 : -1;
}
inline int mod(long long x, int y) {
  if (y == 0) return x;
  if (x < 0) x = -x;
  if (x >= y) x %= y;
  return x;
}
inline int cmod(int x, int y) {
  if (y == 0) return x;
  if (x < 0) x += (abs(x) / y + 1) * y;
  if (x >= y) x = x % y;
  return x;
}
int Bcount(int mask) {
  int n = 0;
  while (mask) n += ((mask & -mask) != 0), mask &= ~(mask & -mask);
  return n;
}
inline bool Bstate(int mask, int idx) { return (mask & (1 << idx)); }
inline int B1(int mask, int idx) { return mask | (1 << idx); }
inline int B0(int mask, int idx) { return mask & ~(1 << idx); }
inline int drift(int mask, int n) { return mask & ((1 << n) - 1); }
void debugmask(int mask, int n) {
  for (int i = 0; i < n; i++) cout << Bstate(mask, i);
}
int dr[4] = {0, 0, -1, 1}, dc[4] = {-1, 1, 0, 0};
template <typename Ty>
void clear(Ty &q) {
  Ty empty;
  swap(q, empty);
}
int main() {
  deque<int> s;
  stack<int> temp;
  int n, m;
  int w[501];
  int vis[501] = {0};
  int o[1001];
  cin >> n >> m;
  for (int i = 0; i < n; i++) cin >> w[i + 1];
  for (int i = 0; i < m; i++) {
    cin >> o[i];
    if (!vis[o[i]]) s.push_back(o[i]), vis[o[i]] = 1;
  }
  int ans = 0;
  for (int i = 0; i < m; i++) {
    while (s.front() != o[i]) {
      ans += w[s.front()];
      temp.push(s.front());
      s.pop_front();
    }
    s.pop_front();
    while (!temp.empty()) {
      s.push_front(temp.top());
      temp.pop();
    }
    s.push_front(o[i]);
  }
  cout << ans << endl;
  return 0;
}
