Maximum Sum in a Sliding Window

Given an array of N integers and an integer K, find the maximum sum of any contiguous subarray of size K. In other words, compute

$$ \max_{0 \leq i \leq N-K} \sum_{j=i}^{i+K-1} A_j $$

You are required to read input from standard input and output the result to standard output.

inputFormat

The first line of input contains two integers N and K separated by a space, where N is the number of elements in the array and K is the window size. The second line contains N space-separated integers representing the array elements.

outputFormat

Output a single integer that represents the maximum sum of any contiguous subarray of length K.

8 3
1 3 -1 -3 5 3 6 7

16