#include<fstream>
#include<iostream>
#include<algorithm>
using namespace std;
ifstream fin("submultimi.in");
ofstream fout("submultimi.out");

int st[18], N;

void Afisare()
{
    int i, ok = 0;
    for (i = 1; i <= N && ok == 0; i++)
        if (st[i] == 1)
            ok = 1;

    if (ok == 0)
    {
        for (i = 1; i <= N; i++)
            if (st[i] == 1)
                fout << i << " ";
        fout << "\n";
    }
}

void Back(int top)
{
    int i;
    if (top == N+1)
        Afisare();
    else
        for (i = 0; i < 2; i++)
        {
            st[top] = i;
            Back(top+1);
        }
}


int main ()
{
    N = 3;
    Back(1);
    return 0;
}