#include <stdio.h>

#define IN "subsir2.in"
#define OUT "subsir2.out"
#define MN 5001
#define inf 1000001
int N,i,min,j,mini,poz;
int V[MN];
int Urm[MN];
int L[MN];

int main()
{
    freopen(IN,"r",stdin);
    freopen(OUT,"w",stdout);
    scanf("%d",&N);
    for (i=1; i<=N; ++i) scanf("%d",&V[i]);
    L[N] = 1;
    for (i=N-1; i >=1; --i)
    {
    min=inf;
    mini=inf;
    poz=0;
    for (j=i+1; j<=N; ++j)
    if (V[j]>V[i]&&V[j]<min)
    {
    if (L[j]==mini) poz=j;
    if (L[j]<mini)
    {
    poz=j;
    mini=L[j];
    }
    min=V[j];
    }
    if (mini==inf) mini=0;
    L[i]=mini+1;
    Urm[i]=poz;    
    }
    min=inf;
    mini=inf;
    for (i=1; i<=N; ++i)
    if (V[i]<min)
    {
    if (mini>L[i]) mini=L[i];
    min=V[i];
    }
    printf("%d",mini);
    return 0;
}