import java.io.*;
import java.util.*;

public class GreatDeceiver {
    void solve() throws IOException {
        long n = nextLong(), k = nextLong();

        long counter = 0;
        long index = (long) Math.floor(Math.log(n) / Math.log(k)) + 1;
        for (; index > 0; --index) {
            long number = (long) Math.pow(k, index - 1);
            long factor = n / number;

            if (factor == 0 || index % 2 == 1) {
                counter += factor * (long) Math.pow(k, index / 2);

                n -= factor * number;
                if (n == 0) {
                    counter++;
                    break;
                }
            } else {
                counter += (long) Math.pow(k, index / 2);

                break;
            }
        }

        out.println(counter);
    }

    void run() throws IOException {
        reader = new BufferedReader(new InputStreamReader(System.in));
        out = new PrintWriter(new OutputStreamWriter(System.out));
         reader = new BufferedReader(new FileReader("great.in"));
         out = new PrintWriter(new FileWriter("great.out"));
        tokenizer = null;
        solve();
        reader.close();
        out.flush();
    }

    public static void main(String[] args) throws IOException {
        new GreatDeceiver().run();
    }

    BufferedReader reader;
    StringTokenizer tokenizer;
    PrintWriter out;

    int nextInt() throws IOException {
        return Integer.parseInt(nextToken());
    }

    long nextLong() throws IOException {
        return Long.parseLong(nextToken());
    }

    double nextDouble() throws IOException {
        return Double.parseDouble(nextToken());
    }

    String nextToken() throws IOException {
        while (tokenizer == null || !tokenizer.hasMoreTokens()) {
            tokenizer = new StringTokenizer(reader.readLine());
        }
        return tokenizer.nextToken();
    }
}