#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
istream &operator>>(istream &is, modint &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint &a) { return os << a.val(); }
istream &operator>>(istream &is, modint998244353 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint998244353 &a) { return os << a.val(); }
istream &operator>>(istream &is, modint1000000007 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint1000000007 &a) { return os << a.val(); } 

typedef long long ll;
typedef vector<vector<int>> Graph;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define FOR(i,l,r) for (int i = l;i < (int)(r); i++)
#define rep(i,n) for (int i = 0;i < (int)(n); i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define my_sort(x) sort(x.begin(), x.end())
#define my_max(x) *max_element(all(x))
#define my_min(x) *min_element(all(x))
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const int INF = (1<<30) - 1;
const ll LINF = (1LL<<62) - 1;
const int MOD = 998244353;
const int MOD2 = 1e9+7;
const double PI = acos(-1);
vector<int> di = {1,0,-1,0};
vector<int> dj = {0,1,0,-1};

#ifdef LOCAL
#  include <debug_print.hpp>
#  define debug(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define debug(...) (static_cast<void>(0))
#endif

using S = ll;
S op(S a, S b){return min(a, b); }
S e(){return LINF; }

int main(){
    cin.tie(0);
    ios_base::sync_with_stdio(false);
    int N, Q; cin >> N >> Q;
    vector<int> A(N);
    rep(i, N) cin >> A[i];
    segtree<S,op,e> dp1(vector<S>(N, LINF));
    segtree<S,op,e> dp2(vector<S>(N, LINF));
    vector<ll> ans(N, LINF);
    dp1.set(0, 0LL);
    dp2.set(0, 0LL);
    rep(i, Q){
        int B; cin >> B;
        vector<ll> nans(N, LINF);
        segtree<S,op,e> ndp1(vector<S>(N, LINF));
        segtree<S,op,e> ndp2(vector<S>(N, LINF));
        rep(j, N){
            if(A[j] == B){
                ll res = min(dp1.prod(0, j) + j, dp2.prod(j, N) - j);
                nans[j] = res;
                ndp1.set(j, nans[j] - j);
                ndp2.set(j, nans[j] + j);
            }
        }
        swap(nans, ans);
        swap(ndp1, dp1);
        swap(ndp2, dp2);
    }

    cout << *min_element(all(ans)) << endl;
}