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.*;
import java.util.*;

public class Main
{
    static int [][]arr;
    static String ReadLn (int maxLg)  // utility function to read from stdin
    {
        byte lin[] = new byte [maxLg];
        int lg = 0, car = -1;
        String line = "";

        try
        {
            while (lg < maxLg)
            {
                car = System.in.read();
                if ((car < 0) || (car == '\n')) break;
                lin [lg++] += car;
            }
        }
        catch (IOException e)
        {
            return (null);
        }

        if ((car < 0) && (lg == 0)) return (null);  // eof
        return (new String (lin, 0, lg));
    }

    public static void main (String args[])  // entry point from OS
    {
        Main myWork = new Main();  // create a dinamic instance
        myWork.Begin();            // the true entry point
    }



    void Begin()
    {
        String input ;;
        StringTokenizer idata;
        int n, m;

        input = Main.ReadLn (255);
        idata = new StringTokenizer (input);
        n = Integer.parseInt (idata.nextToken());
        m = Integer.parseInt (idata.nextToken());
        int count = 0;
while (n>0) {
     count+=n;
    n= n/m;
}
System.out.println(count);





    }
}