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.
n,k = map(int,input().split())
arr = list(map(int,input().split()))
L,j =[] ,0
for i in arr:
	if i <0:
		L.append(i)
	else:
		break
for i in arr:
	if i ==0:
		arr.remove(0)
l = len(L)
#first case
if l>=k and l <= len(arr):
	while k:
		arr[k-1] = arr[k-1]*-1
		k = k-1
	j= sum(arr)
#second case
else:
	if l < k and k <= len(arr):
		i = l
		while i:
			arr[i-1] = arr[i-1]*-1
			i -=1
		arr.sort()
		k = k-l
		while k :
			arr[k-1]= arr[k-1]*-1
			k -=1 
	if l < k and k > len(arr):
		s= k//len(arr)
		t = k%len(arr)
		if s%2 !=0:
			arr = [i*-1 for i in arr]
			arr.sort()
			while t:
				arr[t-1] = arr[t-1]*-1
				t -=1
		else:
			while t:
				arr[t-1] = arr[t-1]*-1
				t -=1
	j = sum(arr) 
print(j)