#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
using namespace std;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
#define rep(i,n) for(int i=0; i<(int)(n); i++)


int main(){
    int N; cin >> N;
    
    vector<int> A(N);
    {
        vector<int> P(N);
        rep(i,N){ cin >> P[i]; P[i]--; }
        vector<int> Q(N);
        rep(i,N){ cin >> Q[i]; Q[i]--; }
        vector<int> invQ(N);
        rep(i,N) invQ[Q[i]] = i;
        rep(i,N) A[i] = invQ[P[i]];
    }

    int K = N;
    rep(i,N-1) if(A[i] + 1 == A[i+1]) K--;

    int ans = 0;
    while((1 << ans) < K) ans++;
    cout << ans << endl;

    return 0;
}


struct ios_do_not_sync{
    ios_do_not_sync(){
        std::ios::sync_with_stdio(false);
        std::cin.tie(nullptr);
    }
} ios_do_not_sync_instance;