#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int INF = 1e9 + 10;
const ll INFL = 4e18;

int main() {
    int N, Q;
    cin >> N >> Q;
    vector<ll> A(N), B(Q);
    for (int i = 0; i < N; i++) {
        cin >> A[i];
    }
    for (int i = 0; i < Q; i++) {
        cin >> B[i];
    }

    vector<vector<ll>> dp(Q + 1, vector<ll>(N + 1, INFL));
    dp[0][0] = 0;
    for (int i = 0; i < Q; i++) {
        vector<ll> pref(N + 1, INFL), suf(N + 1, INFL);
        for (int j = 0; j < N; j++) {
            pref[j + 1] = min(pref[j], dp[i][j] - j);
        }
        for (int j = N - 1; j >= 0; j--) {
            suf[j] = min(suf[j + 1], dp[i][j] + j);
        }
        for (int j = 0; j < N; j++) {
            if (A[j] == B[i]) {
                dp[i + 1][j] = min({dp[i + 1][j], pref[j + 1] + j, suf[j] - j});
            }
        }
    }

    ll ans = INFL;
    for (int i = 0; i <= N; i++) {
        ans = min(ans, dp[Q][i]);
    }
    cout << ans << endl;
}