import java.util.*;

public class Main {
	public static void main (String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] arr = new int[n];
		for (int i = 0; i < n; i++) {
		    arr[i] = sc.nextInt();
		}
		int[] order = new int[n + 1];
		for (int i = 0; i < n; i++) {
		    order[sc.nextInt()] = i;
		}
		int count = 0;
		for (int i = n - 1; i > 0; i--) {
		    for (int j = 0; j < i; j++) {
		        if (order[arr[j]] > order[arr[j + 1]]) {
		            int tmp = arr[j];
		            arr[j] = arr[j + 1];
		            arr[j + 1] = tmp;
		            count++;
		        }
		    }
		}
		System.out.println(count);
   }
}