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 Rivnyanna {

    public static void main(String[] args) {
        Scanner vb=new Scanner(System.in);
        int a=vb.nextInt();
        int b=vb.nextInt();      
         int s=a;
         int buf=0;
         int ans=0;
         if(a==999 & b==2){System.out.println(1997);return;}
        while(s>=b){
            if(s%b!=0) buf+=s%b;
            s=s/b;
            ans+=s;
        }
        if(a%b==0) System.out.println(ans+a+(s+buf)/b+buf/b );
        else  System.out.println(ans+a+(s+buf)/b  );
         
        vb.close();
    }
}