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.*;
//import java.lang.String;
//import java.math.*;
/**
* @author lavlesh
*
*/
public class solution {

	/**
	 * @param args
	 */
	public static void main(String[] args) 
	{
		// TODO Auto-generated method stub
		Scanner in=new Scanner(System.in);
        int a=in.nextInt();
        int b=in.nextInt();
       int nc,hr=a,burnt=0;
       while(a>0)
       {
    	   burnt+=a;
    	   nc=burnt/b;
    	   burnt=burnt%b;
    	   hr+=nc;
    	   a/=b;
       }
        System.out.print(hr);
  
	}
	}
	