#include <bits/stdc++.h>
#define NMAX 5010
#define inf INT_MAX
using namespace std;

ifstream f("subsir2.in");
ofstream g("subsir2.out");

int n,m,v[NMAX],pred[NMAX],d[NMAX],ans[NMAX];

void citire()
{
    f>>n;
    for(int i=1;i<=n;++i)
        f>>v[i];
}

void rezolva_DP_ON_2()
{

    for(int i=0;i<=n;++i)
        pred[i]=-1;

    int pas,Ipas,j;
    for(Ipas=1;Ipas<=n;Ipas<<=1);
    for(int i=1;i<=n;++i)
    {
        pas=Ipas;
        for(j=0;pas;pas>>=1)
            if(j+pas<=m&&v[d[j+pas]]<=v[i])
                j+=pas;
        if(j==m)
            ++m;
        pred[i]=d[j];
        d[j+1]=i;
    }

    g<<m<<"\n";

    int k=m,p=d[m];
    while(p!=-1)
    {
        ans[k--]=p;
        p=pred[p];
    }

    for(int i=1;i<=m;++i)
        g<<ans[i]<<" ";

}

int main()
{
    citire();
    rezolva_DP_ON_2();
    return 0;
}