import java.util.*;
public class Main{
public static void main(String [] args){
Scanner sc = new Scanner(System.in);
int app = sc.nextInt();
int dis = sc.nextInt();
System.out.println(dfs(app,dis));
}
public static int dfs(int n, int m){
if(n ==0 || m ==1){
return 1;
}
if(m > n){
return dfs(n,n);
}
return dfs(n,m-1)+dfs(n-m,m);
}
}