#include <iostream>
#include <cmath>
#include <algorithm>
#include <cstring>
//#pragma GCC optimize (3)
int a[2000], dp[2000];
using namespace std;
int main ()
{
	ios::sync_with_stdio (false);
	cin.tie (0);
	cout.tie (0);
	int n;
	cin >> n;
	for (register int i = 1; i <= n; ++i) cin >> a[i];
	for (register int i = 1; i <= n; ++i)
	{
		int mx = 0;
		for (register int j = 1; j < i; ++j)
			if (a[j] < a[i])
				mx = max (mx, dp[j]);
		dp[i] = mx + 1;
	}
	int mx = 0;
	for (register int i = 1; i <= n; ++i) mx = max (mx, dp[i]);
	cout << mx;
	return 0;
}