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 akash = new Scanner(System.in);
	    int total=akash.nextInt();
	    int creat_with=akash.nextInt();
		int reminder=0;
	    int ans=total;

	    if(total<creat_with){
	    	ans=total;
		}
		else if(total%creat_with==0) {
			while (true) {
				if (total < creat_with) {
					break;
				}
				ans += total / creat_with;
				total = total / creat_with;
			}
		}
		else{
			while(true){
				if (total < creat_with) {
					break;
				}
				reminder+=total%creat_with;
				ans += total / creat_with;
				total = total / creat_with;
			}
			while(reminder>=creat_with){
				ans+=reminder/creat_with;
				reminder=reminder%creat_with;
			}
		}
	    System.out.println(ans);
	    akash.close();
    }
}