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 bisect import bisect_left as bl, bisect_right as br
from collections import defaultdict

input = stdin.readline
read = lambda: map(int, input().strip().split())

n, k = read()
lst = list(read())
x = br(lst, 0)
flag = int(1 < x <= n and lst[x - 1] == 0)
for i in range(min(x, k)):
    lst[i] *= -1
    k -= 1

if k:
    if not flag:
        if k % 2:
            if x == 0:
                lst[x] *= -1
            elif x == n:
                lst[n - 1] *= -1
            else:
                if lst[x] >= lst[x + 1]:
                    lst[x + 1] *= -1
                else:
                    lst[x] *= -1
print(sum(lst))
