#include <bits/stdc++.h>
using namespace std;

#define rep(i, n) for (int i = 0; i < (int)n; i++)
using ll = long long int;
#define INF 1e18

int main() {
  int N, Q;
  cin >> N >> Q;
  vector<int> A(N);
  map<int, vector<int>> a;
  rep(i, N) {
    cin >> A[i];
    a[A[i]].push_back(i);
  }
  vector<int> B(Q + 1);
  B[0] = 0;
  a[0].push_back(0);
  rep(i, Q)
    cin >> B[i + 1];
  vector<ll> dp(N, INF);
  dp[0] = 0;
  rep(i, Q) {
    vector<ll> dp1(N, INF);
    for (int j : a[B[i]]) {
      for (int k : a[B[i + 1]]) {
	dp1[k] = min(dp[j] + abs(k - j), dp1[k]);
      }
    }
    dp = dp1;
  }
  ll ans = INF;
  rep(i, N) {
    if (A[i] == B[Q])
      ans = min(dp[i], ans);
  }
  cout << ans << endl;
  return 0;
}