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

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

//package codeforces;

import java.util.*;

public class Candles {
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        int a=sc.nextInt();
        int b=sc.nextInt();
        int count=a;
        int r=a/b;
        int m=a%b;
        int s=0;
        if(r>=b)
        {
            count+=r;
            while(r>0)
            {
                m+=r%b;
                r=r/b;
                count+=r;
            }
            if(m>=b)
            {
                while(m>0)
                {
                    s+=m%b;
                    m=m/b;
                    count+=m;
                    if(s>=b)
                    {
                        m=s;
                        s=0;
                        continue;
                    }
                }
                
                
            }
        }
        else
            count+=r;
        
        System.out.println("" + count);
    }
    
}
