#include <iostream>
#include <algorithm>
using namespace std;
#define MAX 6

bool orderB( int a, int b)
{
    if(__builtin_popcount(a) == __builtin_popcount(b)){ //Assuming GCC
        int i=0;
        while( (a & (1<<i)) ==(b & (1<<i)) ) i++;
        return((a & (1<<i)) > (b & (1<<i)) );
    }
    else return(__builtin_popcount(a)< __builtin_popcount(b));
}

int main()
{
    int lst[(1<<MAX)];
    int len = sizeof(lst)/sizeof(lst[0]);
    for(int i=0; i<len; i++) lst[i]=i;
    for(int j=0; j < MAX; j++){
        sort(lst, lst + (1<<j), orderB);//Sorting lst array
        for(int i=0; i<(1<<j); i++) cout<<lst[i]<<", ";
    }
return 0;
}