#include <bits/stdc++.h>

using namespace std;

int main(){
int n;
cin>>n;
vector<int>p(n),q(n);
for(auto&e:p)cin>>e,--e;
for(auto&e:q)cin>>e,--e;
vector<int>iq(n);
for(int i=0;i<n;++i)iq[q[i]]=i;

for(int i=0;i<n;++i)p[i]=iq[p[i]],q[p[i]]=i;

int num=0;
for(int i=0;i<n-1;++i)num+=q[i]>q[i+1];

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