#include <iostream>

 #include<cstdio>

 #include<cstring>

 #include<stdlib.h>

 #include<algorithm>

 using namespace std;

 #define LL __int64

 LL dp[][];

 int main()

 {

     int i,j,k,n,d;

     scanf("%d%d",&n,&d);

     for(i = ; i <= n ; i++)

     dp[][i] = ;

     for(i = ; i <= n ; i++)

     {

         for(j = ; j <= n ; j++)

         {

             for(k =  ; k < i ; k++)

             dp[i][j]+=dp[k][j-]*dp[i-k-][j-];

         }

     }

     printf("%I64d\n",dp[n][n]-dp[n][d-]);

     return ;

 }