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
input = sys.stdin.readline

############ ---- Input Functions ---- ############
def inp():
    return(int(input()))
def inlt():
    return(list(map(int,input().split())))
def insr():
    s = input()
    return(list(s[:len(s) - 1]))
def invr():
    return(map(int,input().split()))
############ ---- Input Functions ---- ############

def Roma_and_Changing_Signs():
    n,k = invr()
    seqence = inlt()

    num_pos = []
    num_zero = []
    num_neg = []

    for x in seqence:
        if x>0 :
            num_pos.append(x)
        elif x < 0 :
            num_neg.append(x)
        else:
            num_zero.append(x)

    num_neg_sorted = sorted(num_neg)
    
    index = 0
    while (k>=1) and index <= (n-1):
        num_neg_sorted[index] = -num_neg_sorted[index]
        index += 1
        k -= 1
    
    if k >= 1:
        if k % 2 != 0:
            if len(num_zero) != 0:
                num_neg_sorted[len(num_neg_sorted)-1] = -num_neg_sorted[len(num_neg_sorted)-1]
    
    totalMaxSum = sum(num_pos) + sum(num_neg_sorted)
    print(totalMaxSum)
    return

Roma_and_Changing_Signs()  