18第二次周赛

B

// nuoyanli
#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <vector>

#define inf 0x3f3f3f3f
#define lson l, mid, root << 1
#define rson mid + 1, r, root << 1 | 1
#define min(a, b) a > b ? b : a
#define max(a, b) a < b ? b : a
#define ll long long
using namespace std;
const int N = 1e5 + 10;
struct node {
 ll x, y;
} a[N];
ll pre[N];
bool vis[N];
bool cmp(node a, node b) {
 if (a.x != b.x)
   return a.x < b.x;
 return a.y < b.y;
}
signed main() {
 ll n;
 scanf("%lld", &n);
 for (int i = 1; i <= n; ++i) {
   scanf("%lld", &a[i].x);
 }
 for (int i = 1; i <= n; ++i) {
   scanf("%lld", &a[i].y);
   pre[a[i].y] = i;
 }
 ll l = 1, r = 0, ans = 0;
 for (int i = 1; i <= n; ++i) {
   r = max(r, pre[a[i].x]);
   for (int j = l; j < r; ++j) {
     ans++;
     vis[a[j].y] = 1;
   }
   l = r + 1;
 }
 return !printf("%lld\n", ans);
}