#include <iostream>
#include <fstream>
#define NMAX 5050
using namespace std;
ifstream fin("subsir2.in");
ofstream fout("subsir2.out");
int a[NMAX],b[NMAX],n;
void citire(){int i;
    fin>>n;
    for (i=1;i<=n;i++) fin>>a[i];
}
void solve(){int i,j,lmx;
    b[n]=1;
    for(i=n-1; i>=1; i--)
    {
        lmx=0;
        for(j=i+1; j<=n; j++)
            if(a[i]<a[j]&&b[j]>lmx)lmx=b[j];
        b[i]=lmx+1;
        if(b[i]>lmx)lmx=b[i];
    }
    fout<<lmx;
}
int main()
{
    citire();
    solve();
    return 0;
}