#include <bits/stdc++.h>
using namespace std;
#define m_p make_pair
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
#define fi first
#define se second
typedef long long ll;
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
mt19937 rnf(2106);
const int N = 100005, N0 = 203;
int n;
int a[N], b[N];
int maxi[N0][N0];
int dp[N0][N0][N0];
bool c[N0][N0][N0];
int rec(int l, int r, int ul, int ur, int p)
{
if (l > r)
return 0;
ul = max(ul, l - 1);
ur = min(ur, r + 1);
if (ul + 1 >= ur)
return 0;
int m = maxi[l][r];
if (c[m][ul][ur])
return dp[m][ul][ur];
c[m][ul][ur] = true;
if (ul < m && m < ur && a[m] == b[m])
dp[m][ul][ur] = rec(l, m - 1, ul, ur, m) + rec(m + 1, r, ul, ur, m) + 1;
else
dp[m][ul][ur] = rec(l, m - 1, ul, ur, m) + rec(m + 1, r, ul, ur, m);
if (p == 0)
{
return dp[m][ul][ur];
}
if (p == l - 1)
{
int q = 0;
for (int i = ul + 1; i <= ur - 1; ++i)
{
if (b[i] == a[p])
++q;
if (i < m && m < ur && a[m] == b[m])
++q;
dp[m][ul][ur] = max(dp[m][ul][ur], q + rec(l, m - 1, i, ur, m) + rec(m + 1, r, i, ur, m));
if (i < m && m < ur && a[m] == b[m])
--q;
}
}
else if (p == r + 1)
{
int q = 0;
for (int i = ur - 1; i >= ul + 1; --i)
{
if (b[i] == a[p])
++q;
if (ul < m && m < i && a[m] == b[m])
++q;
dp[m][ul][ur] = max(dp[m][ul][ur], q + rec(l, m - 1, ul, i, m) + rec(m + 1, r, ul, i, m));
if (ul < m && m < i && a[m] == b[m])
--q;
}
}
else
assert(false);
return dp[m][ul][ur];
}
int solv0()
{
memset(c, false, sizeof c);
for (int l = 1; l <= n; ++l)
{
maxi[l][l] = l;
for (int r = l + 1; r <= n; ++r)
{
maxi[l][r] = maxi[l][r - 1];
if (a[r] > a[maxi[l][r]])
maxi[l][r] = r;
}
}
return rec(1, n, 0, n + 1, 0);
}
int p[N];
int ul[N], ur[N];
int solv2()
{
for (int i = 1; i <= n; ++i)
{
p[i] = p[i - 1];
if (a[i] == b[i])
++p[i];
}
ul[0] = 0;
for (int i = 1; i <= n; ++i)
{
if (a[i] > b[i])
{
ul[i] = i;
}
else
{
ul[i] = ul[i - 1];
}
}
ur[n + 1] = n + 1;
for (int i = n; i >= 1; --i)
{
if (a[i] > b[i])
{
ur[i] = i;
}
else
{
ur[i] = ur[i + 1];
}
}
int ans = 0;
for (int i = 1; i <= n; ++i)
{
if (a[i] <= b[i])
{
if (p[ur[i] - 1] - p[ul[i]] > 0)
++ans;
}
}
return ans;
}
void solv()
{
cin >> n;
for (int i = 1; i <= n; ++i)
cin >> a[i];
for (int i = 1; i <= n; ++i)
cin >> b[i];
if (n <= 5000)
{
cout << solv0() << "\n";
return;
}
bool z2 = true;
for (int i = 1; i <= n; ++i)
{
if (b[i] != b[1])
{
z2 = false;
break;
}
}
if (z2)
{
cout << solv2() << "\n";
return;
}
}
int main()
{
#ifdef SOMETHING
freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);
#endif // SOMETHING
ios_base::sync_with_stdio(false), cin.tie(0);
/*int st = 100;
while (st--)
{
n = rnf() % 100 + 1;
for (int i = 1; i <= n; ++i)
{
a[i] = rnf() % 100 + 1;
}
b[1] = a[rnf() % n + 1];
for (int i = 2; i <= n; ++i)
b[i] = b[1];
if (solv0() != solv2())
{
cout << "WA\n";
return 0;
}
}
cout << "OK\n";
return 0;*/
int tt = 1;
//cin >> tt;
while (tt--)
{
solv();
}
return 0;
}
