Maximum Operational Hours for Batteries

You are given N batteries with their respective lifespans (in hours). Your task is to choose exactly K batteries such that the sum of their lifespans is maximized.

The batteries are used as a group in a device that requires exactly K batteries to operate. In mathematical terms, if you pick the battery lifespans \(a_1, a_2, \dots, a_K\) (after sorting in descending order), then the maximum operational hours is given by:

$$\text{Operational Hours} = \sum_{i=1}^{K} a_i$$

Read the input, compute the desired sum, and print the result.

inputFormat

The first line contains two integers N and K, where N is the number of batteries and K is the number of batteries to be used.

The second line contains N space-separated integers representing the lifespans of the batteries.

outputFormat

Output a single integer, which is the maximum operational hours that can be obtained by using exactly K batteries.

## sample

6 3
10 20 30 40 50 60

150

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