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().strip().split()) 

l=list(map(int,input().strip().split()))


ne = []
po= []
zeros=0
for i in l:
	if i<0:
		ne.append(i)
	elif i ==0: 
		zeros+=1 
	else:
		po.append(i)

ne.reverse()
if len(ne)<k:
	ne=[i*-1 for i in ne]
	k-=len(ne)
	if zeros>0:
		k=0
	else:
		if k%2==0:
			k=0
		else:
			ne[-1]*=-1
			k=0
elif len(ne)==k:
	ne=[i*-1 for i in ne ] 
	k=0
else:
	for i in range(0,k     ):
		ne[i]*=-1
print(sum(ne) + sum(po))