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 Main
{
    public static void main( String [] args )
    {
        Scanner is = new Scanner( System.in );
        double a = is.nextShort();
        double b = is.nextShort();
        double accumulator = 0;
        accumulator += a;
        while( a != 0 )
        {
            accumulator += (double)(round( a / b ));
            a = a / b ;
            if( a < b )
                break;
        }
        System.out.println( (short)accumulator );
    }

    public static short round( double a )
    {
        short b = (short)a;
        a = a - (double)b;
        if( a <= 0.5 )
            return b;
        else
            return (short)(b + 1);
    }
}