# include <stdio.h>
# define IN "subsir2.in"
# define OUT "subsir2.out"
int V[5001];
int P[5001];
int N,i,j,max;
int main()
{
freopen(IN,"r",stdin);
freopen(OUT,"w",stdout);
scanf("%d",&N);
for (i = 1; i <= N; ++i) scanf("%d",&V[i]);
P[N]=1;
for (i = N-1; i >= 1; --i)
{
    max = 0;
    for (j = i+1; j<=N; ++j)
      if (V[j]>V[i] && P[j]>max) max=P[j];
    P[i]=max+1;
}
max=0;
for (i=1; i<=N; ++i)
  if (P[i]>max) max=P[i];
printf("%d\n",max);
return 0;
}