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.InputStream;
import java.io.PrintStream;
import java.util.Scanner;

public class CFS379A {

	public final static String IN_FILE = "test/CFS379A.in";
	public final static String OUT_FILE = "test/CFS379A.out";

	public static void main(String[] args) throws Exception {
		// InputStream in = new FileInputStream(IN_FILE);
		//
		// @SuppressWarnings("resource")
		// PrintStream out = new PrintStream(OUT_FILE);

		InputStream in = System.in;
		PrintStream out = System.out;

		Scanner IN = new Scanner(in);

		int a = IN.nextInt();
		int b = IN.nextInt();

		int p = 0;
		int t = 0;
		while (a > 0) {
			t += a;

			int m = (a + p) / b;

			p = a % b;

			a = m;
		}

		out.println(t);
	}
}
