#include <iostream>
#include <string>
#include <vector>
 
using std::cout;
using std::cin;
using std::endl;
using std::string;
using std::vector;
 
 
int main()
{
	int number;
	int m, n;
	cin >> n >> m;
	for(auto i=1; i < (1 << n); i++)
	{
		unsigned short p = i;
		number = 0;
		while(p != 0)
		{
			number += 1 & p;
			p = p >> 1;
		}
		if( number == m)
			cout << i << endl;
	}
 
	return 0;
}