PROSJEK

문제

You are given an array of N integers. Find a consecutive subsequence of numbers of the length at least K that has the maximal possible average.

Please note: the average of a subsequence is the sum of all the numbers in the subsequence divided by its length.

입력

The first line of input contains two integers N (1 ≤ N ≤ 3·10⁵) and K (1 ≤ K ≤ N). The second line of input contains N integers a_i (1 ≤ a_i ≤ 10⁶).

출력

The first and only line of output must contain the maximal possible average. An absolute deviation of ±0.001 from the official solution is permitted.