#include<cstdio>
#include<algorithm>
#define oo 1<<30
#define NMAX 5000+5
using namespace std;
int a[NMAX],p[NMAX],t[NMAX],i,j,n,sol;
int main()
{
    freopen("subsir2.in","r",stdin);
    freopen("subsir2.out","w",stdout);
    scanf("%d",&n);
    for(i=1;i<=n;i++)
    {
        scanf("%d",&a[i]);
        t[i]=oo;
        j=lower_bound(t+1,t+i+1,a[i])-t;
        t[j]=a[i];
        p[i]=j;
        sol=max(sol,j);
    }
    t[sol+1]=n+1;
    for(i=sol;i>=1;i--)
    {
        t[i]=oo;
        for(j=t[i+1];j>=i;j--)
        {
            if(p[j]==i)
            {
                if(t[i]==oo) t[i]=j;
                if(a[t[i]]>a[j]) t[i]=j;
            }
        }
    }
    printf("%d\n",sol);
    for(i=1;i<=sol;i++) printf("%d ",t[i]);
    return 0;
}