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 NewYearSwechi {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scaner = new Scanner(System.in) ;
		int a = scaner.nextInt();
		int b = scaner.nextInt();
		int res = a;
		int f = a/b;
		res+=f;
		while(f>=b)
		{
			f = f/b;
			res+=f;
		}
		
		System.out.println(res);
	}

}
