#include <fstream>

using namespace std;
ifstream f("subsir2.in");
ofstream g("subsir2.out");
int s[5005],n,i,j,a[5005],mn,mnn,mx;
int main()
{
    f>>n;
    for(i=1;i<=n;i++) f>>a[i];
    s[n]=1;
    for(i=n-1;i>=1;i--)
    {
        mx=1000000000;
        mn=0;
        for(j=i+1;j<=n;j++)
        {
            if(a[j]>a[i]&&(s[j]<mn||mn==0)&&a[j]<mx) {mn=s[j];mx=a[j];}
        }
        s[i]=mn+1;
    }
    mn=a[1];
    mnn=s[1];
    for(i=1;i<=n;i++)
    {
        if(a[i]<mn)
        {
            mn=a[i];
            if(mnn<s[i]) mnn=s[i];
        }
    }
    g<<mnn<<'\n';
    return 0;
}