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.
from sys import stdin

from random import randint

#quickSort en segunda posición. El ascending dice si es decreciente o creciente

def quickSort(L, ascending=False):
    if len(L) <= 1:
        return L
    smaller, equal, larger = [], [], []
    pivot = L[randint(0, len(L) - 1)]

    for x in L:
        if abs(x)< pivot:
            smaller.append(x)
        elif abs(x) == pivot:
            equal.append(x)
        else:
            larger.append(x)

    larger = quickSort(larger, ascending=ascending)
    smaller = quickSort(smaller, ascending=ascending)

    if ascending:
        final = smaller + equal + larger
    else:
        final = larger + equal + smaller
    return final


def get_data(n,k,incomes):
    final = quickSort(incomes,ascending=False)
    moves = 0
    for cont in range(n):
        if moves == k:
            break
        if final[cont] < 0:
            final[cont] = final[cont] * -1
            moves += 1
    if moves == k:
        return(sum(final))
    else:
        if (k-moves)%2==0:
            return(sum(final))
        else:
            final[n-1] += -1
            return(sum(final))


def main():
    [n,k] = [int(x) for x in stdin.readline().split()]
    incomes = [int(x) for x in stdin.readline().split()]
    print(get_data(n,k,incomes))

main()