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.io.PrintWriter;
import java.util.Scanner;

public class A {
    static Scanner in; static int next() throws Exception {return in.nextInt();};
    //	static StreamTokenizer in; static int next() throws Exception {in.nextToken(); return (int) in.nval;}
//	static BufferedReader in;
    static PrintWriter out;


    public static void main(String[] args) throws Exception {
        in = new Scanner(System.in);
//		in = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
//		in = new BufferedReader(new InputStreamReader(System.in));
        out = new PrintWriter(System.out);

        int a = next(), b = next();
        int res = a, d = 0;
        while (a != 0) {
            a /= b;
            res += a;
        }
        out.println(res);


        out.close();
    }
}