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.*;

public class Main
{
    public static void main(String args[]) throws java.lang.Exception
    {
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        
        String[] S=br.readLine().split(" ");
        
        Solve(Integer.parseInt(S[0]),Integer.parseInt(S[1]));
    }
    
    static void Solve(int a,int b)
    {
        int time=a,a1=a,safe=0;
        while(a>=b)
        {
            a=(a1+safe)/b;
            safe=(a1+safe)%b;
            time+=a;
            a1=a;
        }
        
        System.out.println(time);
    }
}