import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        new Run();//多余的转移，只是因为main不是构造方法，而且是静态的。一般不用静态main这种方式，但我连这都不会调
    }
}

class Run {
    final int buttToOneNum;

    Run() {
        int total = 0;
        int current;
        {//封定输入范围
            Scanner scanner = new Scanner(System.in);
            current = scanner.nextInt();
            buttToOneNum = scanner.nextInt();
        }
        do {
            total += current;
            current = exchange(current);
        } while (current != 0);
        System.out.println(total);
    }

    int exchange(int buttNum) {
        return buttNum / buttToOneNum;
    }
}