#include <bits/stdc++.h>
using namespace std;

int main(){
	ios::sync_with_stdio(false);
    cin.tie(0);
    int n, ans = 0;
    cin >> n;
    vector<int> a(n), b(n), c(n);
    vector<bool> used(n);
    for(auto &&v : a) cin >> v, v--;
    for(int i = 0; i < n; i++){
        cin >> b[i];
        c[--b[i]] = i;
    }
    for(int i = 0; i < n; i++){
        a[i] = c[a[i]];
        if(a[i] == 0 || !used[a[i] - 1]){
            ans++;
        }
        used[a[i]] = true;
    }
    if(__builtin_popcount(ans) != 1) ans <<= 1;
    cout << __lg(ans) << '\n';
}