#include<iostream>
#include<fstream>
#include<cmath>
#include<algorithm>
#include<vector>
#include<bitset>
#include<cstring>
#include<queue>
#include<stack>

#define ull unsigned long long
#define ll long long
#define pb push_back
#define FOR(a,b,c) for (int a=b;a<=c; ++a)
#define ROF(a,b,c) for (int a=b;a>=c; --a)

using namespace std;
ifstream f("subsir2.in");
ofstream g("subsir2.out");
int N;
int v[5010],rez[5010],sol[5010];

int main()
{
    f>>N;
    FOR (i,1,N) {
        f>>v[i];
    }
    rez[1]=sol[1]=1;
    FOR (i,2,N) {
        rez[i]=1;
        FOR (j,1,i-1) {
            if (v[j]<v[i] && rez[j]+1>rez[i]) {
                rez[i]=rez[j]+1;
            }
        }
        if (v[sol[rez[i]]]>=v[i] || sol[rez[i]]==0) {
            sol[rez[i]]=i;
        }
    }
    int i;
    for (i=1;i<=N;++i) {
        if (sol[i]>sol[i+1]) {
            break;
        }
    }
    g<<i<<'\n';
    FOR (j,1,i) {
        g<<sol[j]<<' ';
    }
    f.close();g.close();
    return 0;
}