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;

/**
 *
 * @author ahmad
 */
public class JavaApplication12 {

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int sum = 0;
        int mod;
        int H;
        int A;
        int O;
        O = input.nextInt();
        A = input.nextInt();
        mod = O % A;
        H = O - mod;
        boolean b = true;
        while (b) {
            if (H % A != 0) {
                H++;
                mod--;
                if (mod < 0) {
                    break;
                }
            }
            sum += H / A;
            if (H / A == 1) {
                break;
            }
            H /= A;
        }
        System.out.println(O + sum);

    }

}
