Fence

1000ms

262144K

Description:

There is a fence in front of Polycarpus's home. The fence consists of n planks of the same width which go one after another from left to right. The height of the i-th plank is h_i meters, distinct planks can have distinct heights.

$\text{[math]}$ Fence for n = 7 and h = [1, 2, 6, 1, 1, 7, 1]

Polycarpus has bought a posh piano and is thinking about how to get it into the house. In order to carry out his plan, he needs to take exactly k consecutive planks from the fence. Higher planks are harder to tear off the fence, so Polycarpus wants to find such k consecutive planks that the sum of their heights is minimal possible.

Write the program that finds the indexes of k consecutive planks with minimal total height. Pay attention, the fence is not around Polycarpus's home, it is in front of home (in other words, the fence isn't cyclic).

Input:

The first line of the input contains integers n and k (1 ≤ n ≤ 1.5·10⁵, 1 ≤ k ≤ n) — the number of planks in the fence and the width of the hole for the piano. The second line contains the sequence of integers h₁, h₂, ..., h_n (1 ≤ h_i ≤ 100), where h_i is the height of the i-th plank of the fence.

Output:

Print such integer j that the sum of the heights of planks j, j + 1, ..., j + k - 1 is the minimum possible. If there are multiple such j's, print any of them.

Sample Input:

7 3
1 2 6 1 1 7 1

Sample Output:

Note:

In the sample, your task is to find three consecutive planks with the minimum sum of heights. In the given case three planks with indexes 3, 4 and 5 have the required attribute, their total height is 8.

Informação

Provedor Codeforces

Código CF363B