#include <cstdio>

using namespace std;

int suma,N,S,sol[257],r=0;

int back(int i) {
    //suma=suma+sol[i];
    if (i==N)
       if (suma==S) r++;
    else {
         sol[i+1]=sol[i]-1;
         //suma=suma+sol[i+1];
         back(i+1);
         //suma=suma+2;
         sol[i+1]=sol[i]+1;
         back(i+1);
    }
    //suma=suma-sol[i];
    return 1;
}

int main() {
    freopen("1-sir.in","r",stdin);
    scanf("%d %d",&N,&S);
    sol[1]=0;
    back(1);
    freopen("1-sir.out","w",stdout);
    printf("%d",r);
    return 0;
}