#include <fstream>
#include <cmath>
using namespace std;
ifstream in ("1-sir.in");
ofstream out ("1-sir.out");
int n, s;
int dps(int n, int s)
{
    if (n==1)
    {
        if (s==0)
            return 1;
        return 0;
    }
    return dps(n-1, abs(s-n+1)) + dps(n-1, s+n-1);
}
int main()
{
    in>>n>>s;
    out<<dps(n, s);
    return 0;
}