# include <fstream>

using namespace std;

# define input "1-sir.in"
# define output "1-sir.out"

# define max 101

long long unsigned  i,x,val,s,k,y,d,rez;
int n,a[1001],c;

int main ()
{
	ifstream fin ( input );
	ofstream fout ( output );

	fin >> n >> d;
	n--;
	y = 1<<n;

	for(i = 0;i<y;i++)
	{
		x = i;

		s = 0;
		val = 0;
		k=n;

		while(x)
		{
			c = x&1;
			a[k--]=c;
			x>>=1;
		}
		for(k = 1;k<=n;k++)
		{
			if(a[k])
				val--;
			else
				val++;
			s+=val;
		}
		if(s == d)
			rez++;

	}
	fout <<rez;

	return 0;
}