#include<stdio.h>
long int n0,s0;
long int sol(long int n,long int s)
{
	if(s<0) return sol(n,-s);
	if(s>((n*(n-1))/2)) return 0;
	if(n==1) { if(s==0) return 1;
		   else return 0;}
	return sol(n-1,s-n+1)+sol(n-1,s+n-1);
}
int main()
{
	FILE *f;
	f=fopen("1-sir.in","r");
	fscanf(f,"%ld%ld",&n0,&s0);
	fclose(f);
	f=fopen("1-sir.out","w");
	fprintf(f,"%ld\n",sol(n0,s0));
	fclose(f);
	return 0;
}