/*
// Sample code to perform I/O:
 
#include <iostream>
 
using namespace std;
 
int main() {
	int num;
	cin >> num;										// Reading input from STDIN
	cout << "Input number is " << num << endl;		// Writing output to STDOUT
}
 
// Warning: Printing unwanted or ill-formatted data to output will cause the test cases to fail
*/
 
// Write your code here
 
#include<bits/stdc++.h>
#include<queue>
using namespace std;
 
int main(){
	
	int n;cin>>n;
	
	queue<int>order;
	int num;
	for(int i=0;i<n;i++){
		cin>>num;
		order.push(num);
	}
	
	queue<int>ideal;
	for(int i=0;i<n;i++){
		cin>>num;
		ideal.push(num);
	}
	
	int operaciones=0;
	while(ideal.size()){
		int quiero=ideal.front();
		int soy=order.front();
		order.pop();
		if(quiero != soy) order.push(soy);
		if(quiero == soy) ideal.pop();
		operaciones++;
	}
	cout<<operaciones<<endl;
		
	return 0;
}