import java.util.*;

 import java.math.*;

 public class Main

 {

     static BigInteger dp[][] = new BigInteger[55][55];

     static void solve(int n, int k) {///函数原来这么用

         for(int i=0; i<=n; ++i)

             for(int j=0; j<=k; ++j)

                 dp[i][j] = BigInteger.ZERO;

         for(int i=0; i<=n; ++i)

             dp[0][i] = BigInteger.ONE;

         for(int i=1; i<=n; ++i) {

             for(int j=1; j<=k; ++j) {

                 for(int p=1; p<=i; ++p) {

                     dp[i][j] = dp[i][j].add(dp[i-p][j].multiply(dp[p-1][j-1]));

                     }

                 }

             }

         }

     public static void main(String[] args) {///主函数

         Scanner in = new Scanner(System.in);

         int cnt = 1;

         while(in.hasNext()) {

             int n = in.nextInt();

             int k = in.nextInt();

             if(n==0 && k==0)

                 break;

             solve(n, k);

             if(cnt > 1)

                 System.out.println("");

             System.out.printf("Case %d: ", cnt++);

             System.out.println(dp[n][k].subtract(dp[n][k-1]));

             }

         }

 }