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.Arrays;
import java.util.Collections;
import java.util.Scanner;

public class main {
    public static void main(String[] args) {

        Scanner scan = new Scanner(System.in);

        int m = 0, s = 0;
        double count = 0, n = 0;

        m = scan.nextInt();
        s = scan.nextInt();
        count = m;
        n = m;

        while(n > 0){

            count = count + (n/s);
            n = n/s;
            if(n == 0) break;
        }

        System.out.println((int)count);

    }
}