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 = list(map(int, input().split()))
sequence = list(map(int, input().split()))

smallerZero = 0
largerZero = 0

sequence.sort()

for i in sequence:
    if i < 0:
        smallerZero += 1
    else:
        largerZero += 1

if smallerZero > k:
    sequence[:k] = map(lambda x: x *-1, sequence[:k])
else:
    sequence[:smallerZero] = map(lambda x: x *-1, sequence[:k])
    if k % 2 != 0:
        sequence.sort()
        sequence[0] = sequence[0]*-1

print(sum(sequence))