Roma works in a company that sells TVs. Now he has to prepare a report for the last year.

Roma has got a list of the company's incomes. The list is a sequence that consists of *n* integers. The total income of the company is the sum of all integers in sequence. Roma decided to perform exactly *k* changes of signs of several numbers in the sequence. He can also change the sign of a number one, two or more times.

The operation of changing a number's sign is the operation of multiplying this number by -1.

Help Roma perform the changes so as to make the total income of the company (the sum of numbers in the resulting sequence) maximum. Note that Roma should perform exactly *k* changes.
The first line contains two integers *n* and *k* (1 ≤ *n*, *k* ≤ 10<sup class="upper-index">5</sup>), showing, how many numbers are in the sequence and how many swaps are to be made.

The second line contains a non-decreasing sequence, consisting of *n* integers *a*<sub class="lower-index">*i*</sub> (|*a*<sub class="lower-index">*i*</sub>| ≤ 10<sup class="upper-index">4</sup>).

The numbers in the lines are separated by single spaces. Please note that the given sequence is sorted in non-decreasing order.
if __name__ == '__main__':
	n, k = map(int, input().split())
	arr = list(map(int, input().split()))
	i = 0
	current_sum = 0
 
	while k > 0:
		#print('Current sum: ', current_sum)
		if arr[i] < 0:
			k -= 1
			arr[i] *= (-1)
			current_sum += arr[i]
 
		elif arr[i] == 0:
			k = 0
			current_sum += sum(arr[i:])
 
		else: #arr[i] > 0
			if k % 2 == 0:
				k = 0
				current_sum += sum(arr[i:])
 
			else: #k odd
				k = 0
				current_sum = max(current_sum + arr[i] - arr[i-1], 
								  current_sum - arr[i])
		
		if i < n:
			i += 1
		else:
			break
			
	current_sum += sum(arr[i:])
	print(current_sum)