#include<fstream>
using namespace std;



void compute(int s[], int idx, int& n, int& sum, int& cnt) {
	if (idx == n + 1) {
		int totalSum = 0;
		for (int i = 1; i <= n; ++i)
			totalSum += s[i];

		if (sum == totalSum)
			cnt++;

		return;
	}

	s[idx] = s[idx - 1] - 1;
	compute(s, idx + 1, n, sum, cnt);

	s[idx] = s[idx - 1] + 1;
	compute(s, idx + 1, n, sum, cnt);
}




int main() 
{
	ifstream in("1-sir.in");
	ofstream out("1-sir.out");

	int n, sum, cnt = 0, s[257];

	in >> n >> sum;
	s[1] = 0;
	compute(s, 2, n, sum, cnt);

	out << cnt;

	return 0;
}