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 A379 {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int a = input.nextInt();
        int b = input.nextInt();
        int candles = a;
        input.close();
        int left = 0;
        while(a!=0 && a!= 1){
            left+=(a % b);
            a/=b;
            if(left > b){
                candles+=(left/b);
                left = (left % b);
            }
            candles+=a;
        }
        System.out.println(candles);
    }
}
