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())

l = [int(i) for i in input().split()]



x = k
i = 0
while x != 0 and i <=n:
    if i ==n:
        if x % 2 !=0:
            if l[i-1] > l[0]:
                j = 0
            else:
                j = i-1
            l[j] = -l[j]
        x = 0
    elif l[i] < 0:
        l[i] = - l[i]
        i += 1
        x -= 1
    else:
        if x % 2 !=0:
            if l[i] > l[0]:
                j = 0
            else:
                j = i
            l[j] = -l[j]
        x = 0


print(sum(l))
