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

if a[0] >= 0:
    if k % 2 == 0:
        print(sum(a))
    else:
        print(sum(a[1:]) - a[0])
else:
    income = 0

    for i in range(n):
        if a[i] < 0:
            if i < n - 1 and a[i + 1] >= 0 and k > 0:
                if k % 2 == 0:
                    if a[i + 1] < -a[i]:
                        income += -a[i] - (2 * a[i + 1])
                    else:
                        income += a[i]
                else:
                    income += -a[i]
                k = 0
                continue
            income += -a[i]
            k -= 1
        else:
            income += a[i]

    print(income)