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;
vector<bool> sieve(long long n) {
  vector<bool> prime(n + 1, true);
  prime[0] = prime[1] = false;
  for (long long i = 2; i <= n; ++i) {
    if (prime[i] && (i * i) <= n)
      for (long long j = i * i; j <= n; j += i) prime[j] = false;
  }
  return prime;
}
long long power(long long a, long long b, long long m = 1000000007) {
  a %= m;
  long long res = 1;
  while (b > 0) {
    if (b & 1) res = res * a % m;
    a = a * a % m;
    b >>= 1;
  }
  return res;
}
int32_t main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long n, m;
  cin >> n >> m;
  vector<long long> b(m);
  map<long long, long long> wt;
  for (long long i = 0; i < n; ++i) {
    long long val;
    cin >> val;
    wt[i + 1] = val;
  }
  for (long long i = 0; i < m; ++i) cin >> b[i];
  vector<long long> a, vis(n + 1, false);
  for (long long i = 0; i < m; ++i) {
    if (!vis[b[i]]) {
      vis[b[i]] = 1;
      a.push_back(b[i]);
      long long len = a.size();
      if (len == n) break;
    }
  }
  long long res = 0;
  for (long long i = 0; i < m; ++i) {
    long long temp = 0;
    long long idx = 0;
    for (long long j = 0; j < n; ++j) {
      if (a[j] == b[i]) {
        idx = j;
        break;
      } else {
        temp += wt[a[j]];
      }
    }
    res += temp;
    for (long long j = idx; j >= 1; --j) {
      a[j] = a[j - 1];
    }
    a[0] = b[i];
  }
  cout << res << '\n';
  return 0;
}
