#include <iostream>
#include <math.h>
using namespace std;

int main(){

	int s[32], i, N;
	cin >> N;

	for(int i=0; i<N; i++)
		cin >> s[i];

	cout << log(N);
	int stop = (int)(log(N));
	//cout << stop;
	for(int i=0; i<pow(2, stop)-1; i++)
		cout << i*2+1 << ", ";


}