D - New Year Candles

Description

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 bwent
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 Input

Input

4 2

Output

7

Input

6 3

Output

8

分析：其实这道题认真读不难的，水题。大意是：a根蜡烛，b根烧剩的蜡烛能变成一根新蜡烛，一根烧一小时，问能烧几小时。
下面给参考代码：
#include <stdio.h>

int main()

{

    int a, b,sum=0,leave=0;

    scanf("%d %d",&a,&b);

    while(a)

    {

        sum+=a;

        leave+=a;

        a=leave/b;

        leave%= b;

    }

    printf("%d\n", sum);

    return 0;

}