#include <bits/stdc++.h>
using namespace std;
#define all(x) (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define rep3(i,m,n) for(int i=(m);i<(n);i++)
#define foreach(x,a) for(auto& (x) : (a) )

#define endl '\n'
#define dump(x)  cout << #x << " = " << (x) << endl;
#define YES(n) cout << ((n) ? "YES" : "NO"  ) << endl
#define Yes(n) cout << ((n) ? "Yes" : "No"  ) << endl
#define POSSIBLE(n) cout << ((n) ? "POSSIBLE" : "IMPOSSIBLE"  ) << endl
#define Possible(n) cout << ((n) ? "Possible" : "Impossible"  ) << endl

#define pb(a) push_back(a)

#define sz(x) ((int)(x).size())
#define in(a,us) (us).find(a)!=(us).end()

template<typename S>
using Vec = vector<S>;

template<typename S, typename T>
using P = pair<S,T>;

template<typename S, typename T, typename U>
using Tpl = tuple<S,T,U>;

using ll = long long;
using ld = long double;

using Pii = P<int, int>;
using Pll = P<ll,ll>;

using Tiii = Tpl<int,int,int>;
using Tll = Tpl<ll,ll,ll>;

using Vi = Vec<int>;
using VVi = Vec<Vi>;

template<typename S, typename T>
using umap = unordered_map<S,T>;

template<typename S>
using uset = unordered_set<S>;

using Graph = VVi;

int main(){
    cin.tie(0)->sync_with_stdio(0);
    int n;
    cin >> n;
    Vi a(n),b(n);
    rep(i,n) cin >> a[i];
    rep(i,n) cin >> b[i];
    umap<int,int> um;
    rep(i,n) um[a[i]] = i;
    Vi c(n);
    rep(i,n) c[i] = um[b[i]];
    uset<int> s;
    rep(i,n){
        if (in(c[i]-1,s)) {
            s.erase(s.find(c[i]-1));
            s.insert(c[i]);
        } else {
            s.insert(c[i]);
        }
    }
    int sz = s.size();
    int ans = 0;
    while (sz>1){
        sz = (sz+1)/2;
        ans++;
    }
    cout << ans << endl;
 }