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;
int const siz = 1e9, bound = 1e5, mod = siz + 7;
long long const cnt = 1e18;
int w[501], dd[1001];
set<int> ee;
map<int, int> freq;
vector<pair<int, int> > occ;
vector<int> trr;
int n, m;
bool comp(pair<int, int> a, pair<int, int> b) {
  if (a.first == b.first)
    return find(dd, dd + m, a.second) < find(dd, dd + m, b.second);
  return a.first > b.first;
}
int main() {
  scanf("%d", &n), scanf("%d", &m);
  for (int(i) = 1; (i) <= (n); (i)++) scanf("%d", &w[i]);
  for (int(i) = 0; (i) < (m); (i)++) scanf("%d", &dd[i]);
  for (int(i) = 0; (i) < (m); (i)++) freq[dd[i]]++;
  for (map<int, int>::iterator it = freq.begin(); it != freq.end(); it++)
    occ.push_back(make_pair((it->second), (it->first)));
  sort(occ.begin(), occ.end(), comp);
  for (int(i) = 0; (i) < (occ.size()); (i)++) trr.push_back(occ[i].second);
  long long carry = 0;
  for (int(i) = 0; (i) < (m); (i)++) {
    int idx = find(trr.begin(), trr.end(), dd[i]) - trr.begin();
    for (int(j) = 0; (j) < (idx); (j)++) carry += w[trr[j]];
    int rem = trr[idx];
    trr.erase(trr.begin() + idx);
    trr.insert(trr.begin(), rem);
  }
  printf("%lld\n", carry);
  return 0;
}
