#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{
  int n, q;
  cin >> n >> q;
  vector<int> a(n);
  for (int i = 0; i < n; ++i) cin >> a[i];
  auto all = a;
  sort(all.begin(), all.end());
  all.erase(unique(all.begin(), all.end()), all.end());
  int siz = all.size();
  vector<vector<int>> id(siz);
  for (int i = 0; i < n; ++i)
  {
    int idx = lower_bound(all.begin(), all.end(), a[i]) - all.begin();
    id[idx].push_back(i);
  }
  vector<int> dp(n, 1e9);
  dp[0] = 0;
  while (q--)
  {
    int b;
    cin >> b;
    int idx = lower_bound(all.begin(), all.end(), b) - all.begin();
    vector<int> ndp(n, 1e9);
    for (int i = 0; i < n; ++i)
    {
      int id2 = lower_bound(id[idx].begin(), id[idx].end(), i) - id[idx].begin();
      int li = -1, ri = -1;
      if (id2 < id[idx].size()) ri = id[idx][id2];
      --id2;
      if (id2 >= 0) li = id[idx][id2];
      if (li >= 0) ndp[li] = min(ndp[li], dp[i] + abs(li - i));
      if (ri < n) ndp[ri] = min(ndp[ri], dp[i] + abs(ri - i));
    }
    swap(ndp, dp);
  }
  int ans = 1e9;
  for (int i = 0; i < n; ++i) ans = min(ans, dp[i]);
  cout << ans << endl;
}