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.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.util.HashMap;
import java.util.Iterator;
import java.util.StringTokenizer;
import java.util.TreeMap;
import java.util.TreeSet;
import sun.reflect.generics.tree.Tree;

public class Main {

    public static void main(String[] args) throws IOException {
        PrintWriter pw = new PrintWriter(System.out);
        Scanner sc = new Scanner();
        int a=Integer.parseInt(sc.next());
        int b=Integer.parseInt(sc.next());
        int div=a/b;
        int rta=a;
        while(div>0){
            rta+=div;
            div/=b;
        }
        System.out.println(rta);
                

    }

    static class Scanner {

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer("");
        int spaces = 0;

        public String nextLine() throws IOException {
            if (spaces-- > 0) {
                return "";
            } else if (st.hasMoreTokens()) {
                return new StringBuilder(st.nextToken("\n")).toString();
            }
            return br.readLine();
        }

        public String next() throws IOException {
            spaces = 0;
            while (!st.hasMoreTokens()) {
                st = new StringTokenizer(br.readLine());
            }
            return st.nextToken();
        }

        public boolean hasNext() throws IOException {
            while (!st.hasMoreTokens()) {
                String line = br.readLine();
                if (line == null) {
                    return false;
                }
                if (line.equals("")) {
                    spaces = Math.max(spaces, 0) + 1;
                }
                st = new StringTokenizer(line);
            }
            return true;
        }
    }
}
