1.5 \(s / 256\) \(MB / 130\) points

1 vs. 100 is a quiz that we could follow on TVs a few years ago. For the purposes of this task, we will

slightly simplify the quiz rules.

The contestant answers questions and has to throw out 100 people who compete against him.

Everyone responds to the same question in each round and those who answer the question wrong

are thrown out. The amount of money that a competitor who manages to throw out all 100 opponents

gets is equal to the sum of money won per round. In each round, all opponents are worth equally and

all opponents combined are worth 100 000 kunas (Croatian currency). The amount earned in a round

is equal to the sum of the values of people who have been thrown out in that round. For example, if

there are 10 opponents at some point, each of them is worth 10 000 kunas, and the contestant will

get 30 000 kunas if he or she manages to throw out 3 opponents in that round.

Let's say that the quiz is called 1 vs. \(N\) (i.e. the competitor competes against \(N\) people) and that Mirko

M. managed to throw all the opponents in exactly \(K\) rounds. What is the maximum amount he could

have won?

In the sample tests totally worth 20 points it will be true that \(N\) ≤ 100.
In the sample tests totally worth additional 45 points it will be true that \(N\) ≤ 3 000.

In the only line there are the integer numbers \(N\) (1 ≤ \(N\) ≤ 100 000) and \(K\) (1 ≤ \(K\) ≤ \(N\) ), the numbers
from the task description.

Print the maximum possible amount that Mirko M. could have won divided by 100 000 .
Your answer will be considered correct if relative or absolute difference from the official answer is at

most 10 ^{-8}{ }.

생성자가 기록되지 않았습니다.

출처 COCI 2018/2019 Contest 4