Problem:
Score : 200 points

Problem Statement

Snuke has N sticks.
The length of the i-th stick is l_i.

Snuke is making a snake toy by joining K of the sticks together.

The length of the toy is represented by the sum of the individual sticks that compose it.
Find the maximum possible length of the toy.

Constraints

1 \leq K \leq N \leq 50

1 \leq l_i \leq 50

l_i is an integer.

Input

Input is given from Standard Input in the following format:

N K
l_1 l_2 l_3 ... l_{N}

Output

Print the answer.

Sample Input 1

5 3
1 2 3 4 5

Sample Output 1

12

You can make a toy of length 12 by joining the sticks of lengths 3, 4 and 5, which is the maximum possible length.

Sample Input 2

15 14
50 26 27 21 41 7 42 35 7 5 5 36 39 1 45

Sample Output 2

386

Solution in Ruby (2.3.3) (judge verdict: Accepted)

class Array
    def quick_sort
    return self if self.length <= 1
    pivot = pop
    left, right = partition { |e| e < pivot }
    push pivot
    left.quick_sort + [pivot] + right.quick_sort
  end
end

n, k = gets.chomp.split(' ').map(&:to_i)
sticks = gets.chomp.split(' ').map(&:to_i)
total = 0

sticks.quick_sort.reverse[0..(k-1)].each do |stick|
  total += stick
end
puts total