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.
import sys
import math
from collections import defaultdict
import itertools

MAXNUM = math.inf
MINNUM = -1 * math.inf


def getInt():
    return int(sys.stdin.readline().rstrip())


def getInts():
    return map(int, sys.stdin.readline().rstrip().split(" "))


def getString():
    return sys.stdin.readline().rstrip()


def printOutput(ans):
    sys.stdout.write()
    pass


def solve(ans):
    pass


def hasZero(lst):
    for ele in lst:
        if ele == 0:
            return True
    return False


def readinput():
    n, k = getInts()
    lst = list(getInts())
    for i in range(len(lst)):
        """largest negs appear at front of list"""
        if lst[i] < 0 and k > 0:
            lst[i] *= -1
            k -= 1

    if k == 0 or k % 2 == 0 or hasZero(lst):
        return sum(lst)

    return sum(lst) - 2 * min(lst)


print(readinput())
