/**
   @version 1.10 1999-12-17
   @author Cay Horstmann
*/

import javax.swing.*;

public class LotteryOdds
{  
   public static void main(String[] args)
   {  
      String input = JOptionPane.showInputDialog
         ("How many numbers do you need to draw?");
      int k = Integer.parseInt(input);

      input = JOptionPane.showInputDialog
         ("What is the highest number you can draw?");
      int n = Integer.parseInt(input);

      /* 
         compute binomial coefficient
         n * (n - 1) * (n - 2) * . . . * (n - k + 1)
         -------------------------------------------
         1 * 2 * 3 * . . . * k
      */

      int lotteryOdds = 1;
      for (int i = 1; i <= k; i++)
         lotteryOdds = lotteryOdds * (n - i + 1) / i;

      System.out.println
         ("Your odds are 1 in " + lotteryOdds + ". Good luck!");

      System.exit(0);
   }
}