# include <cstdio>
using namespace std;
FILE *f=freopen("1-sir.in","r",stdin);
FILE *g=freopen("1-sir.out","w",stdout);
int n,s=0,nr;
void back(int k,int suma,int last)
{
    if (k==n+1)
    {
        if (suma==s) nr++;
    }
    else
    {
        suma+=last+1;
        back(k+1,suma,last+1);
        suma-=2;
        back(k+1,suma,last-1);
    }
}
int main()
{
    scanf("%d%d",&n,&s);
    back(2,0,0);
    printf("%d",nr);
    return 0;
}