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);
		int i = sc.nextInt();
		int j = sc.nextInt();
		int res = i;
		while (i >= 1)
		{
			res += (i/j);
//			System.out.println("i="+i+", res="+res);
			i /= j;
		}
		System.out.println(res);
		sc.close();
	}
}

 		 		 	 					 	   	 	 	 	    	