#include <bits/stdc++.h>   using namespace std;   const int MAXN = 2 * (100000) + 5;   int a[MAXN], b[MAXN];   int main() {     int n;     cin >> n;     for (int i = 0; i < n; ++i) cin >> a[i];     for (int i = 0; i < n; ++i) cin >> b[i];     int res = 0;     int j = 0;     for (int i = 0; i < n && j < n; ++i) {       while (j < n && a[i] != b[j]) {         j++;         res++;       }       j++;     }     cout << res << endl;     return 0;   }   