#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < (int)n; i++)
using ll = long long;

int main(){
  int n;
  cin >> n;
  int a[n], b[n];
  rep(i,n) cin >> a[i];
  rep(i,n) cin >> b[i];
  int ans = 0;
  int p = 0;
  while(p < n) {
    if(a[p] == b[p]) p++;
    else {
      while(p < n && a[p] != b[p]) p++;
      ans++;
    }
  }
  cout << ans << endl;
  return 0;
}