#include <bits/stdc++.h>
using namespace std;
int n;
vector<int> a;
vector<int> b;
void solve_bf() {
}
void solve_bequal() {
int x = b[1];
int last = 0;
bool ok = false;
int ans = 0;
a.push_back(x + 1);
for(int i = 1; i <= (n + 1); ++i) {
if(a[i] > x) {
if(ok) {
ans += i - last - 1;
ok = false;
}
last = i;
} else if(a[i] == x) {
ok = true;
}
}
cout << ans << "\n";
}
void solve_astrictlyincreasing() {
vector<int> dp(1 + n, 0);
vector<bool> ok(1 + n, false);
for(int i = 1; i <= n; ++i) {
dp[i] = dp[i - 1];
if(a[i] == b[i]) {
++dp[i];
ok[i] = true;
}
int cur = dp[i];
int l = i;
for(int j = i - 1; j >= 1; --j) {
if(ok[j]) --cur;
if(a[i] == b[j]) ++cur;
if(cur > dp[i]) {
dp[i] = cur;
l = j;
}
}
for(int j = i - 1; j >= l; --j) {
if(a[i] == b[j]) ok[j] = true;
else ok[j] = false;
}
}
cout << dp[n] << "\n";
}
void solve() {
cin >> n;
a.assign(1 + n, 0);
b.assign(1 + n, 0);
for(int i = 1; i <= n; ++i) cin >> a[i];
for(int i = 1; i <= n; ++i) cin >> b[i];
set<int> b_set;
for(int i = 1; i <= n; ++i) {
b_set.insert(b[i]);
}
/*if(n <= 10) {
solve_bf();
} else */if(b_set.size() == 1) {
solve_bequal();
} else {
solve_astrictlyincreasing();
}
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
solve();
return 0;
}
