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;
bool isprime(long long n) {
  for (long long i = 2; i <= sqrt(n); i++) {
    if (n % i == 0) return false;
  }
  return true;
}
bool prm[10000007];
long long N = 10000000;
void sieve() {
  prm[1] = 1;
  for (long long i = 2; i <= sqrt(N); i++) {
    if (prm[i] == 0) {
      for (long long j = i + i; j <= N; j = j + i) prm[j] = 1;
    }
  }
}
long long bm(long long b, long long p) {
  long long namira;
  if (p == 0) return 1;
  if (p % 2 == 0) {
    namira = bm(b, p / 2);
    return ((namira % 1000000007) * (namira % 1000000007)) % 1000000007;
  } else {
    return ((b % 1000000007) * (bm(b, p - 1) % 1000000007)) % 1000000007;
  }
}
int main() {
  long long i, n, m, c, p, x, a[510], A[510], b[1010], k, j;
  scanf("%I64d%I64d", &n, &m);
  for (i = 1; i <= n; i++) {
    scanf("%I64d", &a[i]);
  }
  scanf("%I64d", &b[0]);
  k = 1;
  for (i = 1; i < m; i++) {
    scanf("%I64d", &x);
    if (x != b[k - 1]) {
      b[k] = x;
      k++;
    }
  }
  c = 0;
  for (i = 1; i < k; i++) {
    for (j = 1; j <= n; j++) A[j] = 1;
    for (j = i - 1; j >= 0; j--) {
      if (b[i] == b[j]) {
        break;
      } else {
        if (A[b[j]] != 0) {
          A[b[j]] = 0;
          c += a[b[j]];
        }
      }
    }
  }
  printf("%I64d\n", c);
  return 0;
}
