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>
T gcd(T a, T b) {
  return (b != 0 ? gcd<T>(b, a % b) : a);
}
template <class T>
T lcm(T a, T b) {
  return (a / gcd<T>(a, b) * b);
}
long long pwr(long long base, long long p) {
  long long ans = 1;
  while (p) {
    if (p & 1) ans = (ans * base) % (1000000007LL);
    base = (base * base) % (1000000007LL);
    p >>= 1;
  }
  return ans;
}
long long modInv(long long n, long long mod) { return pwr(n, mod - 2); }
int bitCount(int n) {
  int c = 0;
  while (n) {
    c++;
    n &= n - 1;
  }
  return c;
}
int main() {
  int n, m, i;
  cin >> n >> m;
  pair<int, int> arr[n + 9];
  int order[m + 9];
  long long sum[m + 9];
  for (i = 0; i < n; i++) {
    scanf("%d", &arr[i].second);
    arr[i].first = i + 1;
  }
  int fir[n + 9];
  memset(fir, -1, sizeof(fir));
  for (i = 0; i < m; i++) {
    scanf("%d", &order[i]);
    if (i == 0)
      sum[i] = arr[order[i] - 1].second;
    else
      sum[i] = sum[i - 1] + arr[order[i] - 1].second;
    if (fir[arr[order[i] - 1].first] == -1) {
      fir[arr[order[i] - 1].first] = i;
    }
  }
  long long ans = 0;
  for (i = 0; i < m; i++) {
    if (fir[arr[order[i] - 1].first] == i) {
      if (i > 0)
        ans = sum[i - 1] + ans;
      else {
        ans = 0;
      }
    } else {
      int x = fir[arr[order[i] - 1].first];
      int k = 0;
      int temp = 0;
      set<int> s;
      for (k = x + 1; k < i; k++) {
        if (s.find(arr[order[k] - 1].first) == s.end() &&
            arr[order[i] - 1].first != arr[order[k] - 1].first) {
          s.insert(arr[order[k] - 1].first);
          temp = temp + arr[order[k] - 1].second;
        }
      }
      ans += temp;
      fir[arr[order[i] - 1].first] = i;
    }
  }
  cout << ans;
  return 0;
}
