#include <bits/stdc++.h>
//#include <atcoder/all>
using namespace std;
//using namespace atcoder;
//using mint = modint1000000007;
//const int mod = 1000000007;
//using mint = modint998244353;
//const int mod = 998244353;
const int INF = 1e9;
//const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i,l,r)for(int i=(l);i<(r);++i)
#define rrep(i, n) for (int i = (n) - 1; i >= 0; --i)
#define rrep2(i,l,r)for(int i=(r) - 1;i>=(l);--i)
#define all(x) (x).begin(),(x).end()
#define allR(x) (x).rbegin(),(x).rend()
#define P pair<int,int>
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int n, q; cin >> n >> q;
	vector<int>a(n), b(q);
	rep(i, n)cin >> a[i];
	rep(i, q)cin >> b[i];
	map<int, vector<int>>pos;
	rep(i, n) pos[a[i]].push_back(i);
	vector<P>dp = { { 0,0 } };
	rep(i, q) {
		vector<P>ndp;
		for (auto e : pos[b[i]]) {
			ndp.emplace_back(e, INF);
		}
		for (auto e : dp) {
			//以下の数
			int count = upper_bound(all(pos[b[i]]), e.first) - pos[b[i]].begin();
			if (0 != count) {
				int d = e.second + abs(ndp[count - 1].first - e.first);
				chmin(ndp[count - 1].second, d);
			}
			if (ndp.size() != count) {
				int d = e.second + abs(ndp[count].first - e.first);
				chmin(ndp[count].second, d);
			}
		}


		// naive
		/*rep(j, dp.size()) {
			rep(k, ndp.size()) {
				int d = dp[j].second + abs(dp[j].first - ndp[k].first);
				chmin(ndp[k].second, d);
			}
		}*/
		swap(dp, ndp);
	}
	int ans = INF;
	for (auto e : dp)chmin(ans, e.second);
	cout << ans << endl;
	return 0;
}