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()))
i = 0
ans = 0
while k != 0:
    if a[i] < 0:
        k -= 1
        ans += -a[i]
    else:
        if k % 2 == 0:
            k = 0
            ans += a[i]
        else:
            k = 0
            if i != 0:
                if -a[i-1] > a[i]:
                    ans += -a[i]
                else:
                    ans += 2*a[i-1] + a[i]
            else:
                ans += -a[i]
    i += 1
for u in range(i, n):
    ans += a[u]
print(ans)