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 = [int(x) for x in sys.stdin.readline().strip().split()]
arr = [int(x) for x in sys.stdin.readline().strip().split()]
count = 0
index = -1
for i in range(0,n):
	if arr[i]<=0:
		count+=-arr[i]
		k-=1
		k = max(0,k)
		index = i

	else:
		break
if index!=-1:
	count = count+arr[index]

if k%2==0 and k!=0:
	if index!=-1:
		count+=-arr[index]
	for i in range(index+1,n):
		count+=arr[i]
else:
	if index!=-1:
		if index+2<=n and -arr[index]>arr[index+1]:
			count+=-arr[index]-arr[index+1]
			for i in range(index+2,n):
				count+=arr[i]
	else:
		count+=-arr[0]
		for i in range(1,n):
			count+=arr[i]
print(count)
