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()))
arr = list(map(int, input().split()))
arr.sort()
cunt = 0
t = 0
if len(arr) == 1 and arr[0] < 0:
    if k%2 != 0:
        print(abs(arr[0]))
    else:
        print(arr[0])
else:
    while t < min(n, k):
        if arr[t] < 0:
            arr[t] *= -1
            t += 1
        else:
            arr.sort()
            if (k-t) % 2 != 0:
                arr[0] *= -1
            break
    print(sum(arr))