/* Solution to price is right by bob roos */

import java.io.*;
import java.util.*;

public class BG {
  public static int casenum;
  public static int G, L;
  public static BufferedReader in;

  public static int value() {
    int a[][] = new int[31][31];
    int g,l;
  
    if (L > G)
      L = G;
    for (g = 1; g <= G; g++)
      a[0][g] = g;
    for (l = 1; l <= L; l++)
    {
      a[l][l] = a[l-1][l];
      for (g = l+1; g <= G; g++)
        a[l][g] = 1 + a[l][g-1] + a[l-1][g-1];
    }
    return a[L][G];
  }


  public static void main(String[] args) throws Exception {
    in = new BufferedReader(new InputStreamReader(System.in));
    StringTokenizer tok;
    casenum = 0;
    while (true) {
      String line = in.readLine();
      tok = new StringTokenizer(line);
      G = Integer.parseInt(tok.nextToken().trim());
      L = Integer.parseInt(tok.nextToken().trim());
      if (G <= 0) break;
      casenum++;
      System.out.println("Case " + casenum + ": " + value());
    }
  }
}