import java.util.Scanner;

/**
 * Vasily the Programmer loves romance, so this year he decided to illuminate
 * his room with candles.
 * 
 * Vasily has a candles.When Vasily lights up a new candle, it first burns for
 * an hour and then it goes out. Vasily is smart, so he can make b went out
 * candles into a new candle. As a result, this new candle can be used like any
 * other new candle.
 * 
 * Now Vasily wonders: for how many hours can his candles light up the room if
 * he acts optimally well? Help him find this number.
 * 
 * Input 
 * The single line contains two integers, a and b (1 ≤ a ≤ 1000;
 * 2 ≤ b ≤ 1000).
 * 
 * Output 
 * Print a single integer — the number of hours Vasily can light up the
 * room for.
 * 
 * Sample test(s) 
 * input 
 * 4 2 
 * output 
 * 7 
 * input 
 * 6 3 
 * output 
 * 8 
 * Note 
 * Consider the first sample. 
 * For the first four hours Vasily lights up new candles, then he uses
 * four burned out candles to make two new ones and lights them up. When these
 * candles go out (stop burning), Vasily can make another candle. Overall,
 * Vasily can light up the room for 7 hours.
 * 
 * @Title: A379NewYearCandles.java
 * @author lxh
 * @date Aug 18, 2015 9:23:55 AM
 * 
 */

public class Main {
	public static void main(String[] args) {
		Scanner cin = new Scanner(System.in);
		int a = cin.nextInt();
		int b = cin.nextInt();
		int s = a;
		while (a>=b) {
			s += a / b;
			a =a/b+a%b;
		}
		System.out.println(s);
	}
}
