5 3
 1000 3
 777 17
 4 3
 2 2
 100 4
 10 4
 999 2
 6 4
 1 2
 17 3
 1 4
 26 8
 91 5
 1 3
 1000 2
 20 3
 9 4
 123 5
 1000 1000
 3 2
 3 3
 80 970
 1000 4
 1 1000

7
 1499
 825
 5
 3
 133
 13
 1997
 7
 1
 25
 1
 29
 113
 1
 1999
 29
 11
 153
 1001
 5
 4
 80
 1333
 1

import java.util.Scanner;
public class main {


    public static void main(String[] args) {
         Scanner SC = new Scanner(System.in);
         String [] Data = SC.nextLine().split("\\s+");
         int a = Integer.parseInt(Data[0]);
         int b = Integer.parseInt(Data[1]);
         int hours = a;
         int candles = a;
         int candlesused = a;
         while(candles / b >0)
         {
             candles = candlesused / b;
             candlesused = 0;
             hours += candles;
             candlesused = candles;
         }
         System.out.println(hours);
    }
    
}