#include <iostream>
using namespace std;

int N =3, subm[25];
void gen(int element, int lgSubm) {
  if (element == N + 1) {
    for (int i = 0; i < lgSubm; ++i)
      cout<<subm[i]<<' ';
    cout<<"\n";
    return;
  }
  subm[lgSubm] = element;
  gen(element + 1, lgSubm + 1);
  gen(element + 1, lgSubm);
}
int main(){
gen(1,0);
}