A9341 | New Year Candles

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.

The single line contains two integers, $a$ and $b$ $(1<=a<=1000; 2<=b<=1000)$ .

Print a single integer — the number of hours Vasily can light up the room for.