#include <vector>
#include <iostream>
#include <map>
using namespace std;

int main () {
    ios_base::sync_with_stdio(false);
    int n;
    cin >> n;

    vector<int> A(n), B(n), idx(n + 1);

    for(int i = 0; i < n; i++) {
        cin >> A[i];
        idx[A[i]] = i;
    }

    for(int i = 0; i < n; i++) {
        cin >> B[i];
    }

    int res = 0;
    for(int i = 0; i < n; i++) {
        if(A[i] != B[i]) {
            int tmp = idx[B[i]], tmp2 = A[i];
            swap(A[i], A[tmp]);
            idx[A[i]] = i;
            idx[tmp2] = tmp;
            res++;
        }
    }

    cout << res << endl;

    return 0;
}