#include<fstream>
using namespace std;

long a[5001],b[5001],c[5001],n,i,j,maxx;
ifstream f("subsir2.in");
ofstream g("subsir2.out");
int maxim(long a,long b)
{
	if (a>b) return a;
	return b;
}
int main()
{
	f>>n;
	for(i=1;i<=n;i++)
		f>>a[i];
	for(i=1;i<=n;i++)
		b[i]=1;
	for(i=n-1;i>=1;i--)
		for(j=i+1;j<=n;j++)
		{
			if(a[i]<a[j]&&b[i]<=b[j])
				{
					b[i]++;
					c[i]=j;
					maxx=maxim(b[i],maxx);
				}
		}
	i=0;
	g<<maxx;
	f.close();
	g.close();
	return 0;
}