#include <fstream>
#include <climits>
#define inf INT_MAX
using namespace std;

ifstream fin("subsir2.in");
ofstream fout("subsir2.out");

long long n,i,a[5101],l[5101],j,Max,k,poz,Min;

int main()
{
    fin>>n;
    for(i=1;i<=n;i++)
        fin>>a[i];
    for(i=n;i>0;i--)
    {
        for(j=i+1,Min=inf;j<=n;j++)
            if(a[j]>a[i]&&a[j]<Min)
        {
            Min=min(Min,a[j]);
            l[i]=min(l[i],l[j]+1);
            if(!l[i])l[i]=l[j]+1;
        }
        if(l[i]==0)l[i]=1;
    }
    for(i=1,Min=inf,Max=inf;i<=n;i++)
    {
        if(a[i]<Min){Min=a[i];Max=min(Max,l[i]);}
    }
    fout<<Max<<'\n';
    for(k=Max;k>0;k--)
    {
        Min=inf;
        for(i=poz+1;i<=n;i++)
            if(l[i]==k&&a[i]<Min)
        {
            Min=a[i];
            poz=i;
        }
        fout<<poz<<" ";
    }
    return 0;
}