#include <bits/stdc++.h>

using namespace std;
void fast_io() {
    ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
}

int main() {
    fast_io();
    int n, q;
    cin >> n >> q;
    vector<int> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    const long long INF = 1e18;
    vector<int> b(q);
    for (int i = 0; i < q; i++) {
        cin >> b[i];
    }
    vector<long long> dp(n, INF);
    dp[0] = 0;
    for (int j = 0; j < q; j++) {
        vector<long long> new_dp(n, INF);
        vector<long long> dp_m(n), dp_p(n);
        for (int i = 0; i < n; i++) {
            dp_m[i] = dp[i] - i;
            if (i > 0) {
                dp_m[i] = min(dp_m[i], dp_m[i - 1]);
            }
        }
        for (int i = n - 1; i >= 0; i--) {
            dp_p[i] = dp[i] + i;
            if (i + 1 < n) {
                dp_p[i] = min(dp_p[i], dp_p[i + 1]);
            }
        }
        for (int i = 0; i < n; i++) {
            if (a[i] != b[j]) {
                continue;
            }
            new_dp[i] = min(dp_m[i] + i, dp_p[i] - i);
        }
        // for (auto e : dp) {
        //     cout << e << " ";
        // }
        // cout << endl;
        swap(dp, new_dp);
    }

    long long ans = *min_element(dp.begin(), dp.end());
    cout << ans << endl;
}