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 {
 
    FastScanner in;
    PrintWriter out;
 
    void solve() {
        int a = in.nextInt();
        int b = in.nextInt();
        
        int hour = a;
        int sum = a;
        while(hour>0){
            hour = hour/b;
            sum+=hour;
        }

        out.println(sum);
    }
 
    void run() {
        in = new FastScanner();
        out = new PrintWriter(System.out);
        solve();
        out.close();
    }
 
    class FastScanner {
        BufferedReader br;
        StringTokenizer st;
 
        public FastScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }
 
        public FastScanner(String s) {
            try {
                br = new BufferedReader(new FileReader(s));
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
        }
 
        String nextToken() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }
 
        int nextInt() {
            return Integer.parseInt(nextToken());
        }
 
        long nextLong() {
            return Long.parseLong(nextToken());
        }
 
        double nextDouble() {
            return Double.parseDouble(nextToken());
        }
    }
 
    public static void main(String[] args) {
        new Main().run();
    }
}