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.
'''
# Submitted By M7moud Ala3rj
Don't Copy This Code, CopyRight . [email protected] © 2022-2023 :)
'''
# Problem Name = "Roma and Changing Signs"
# Class: B

import sys
#sys.setrecursionlimit(2147483647)
input = sys.stdin.readline
def print(*args, end='\n', sep=' ') -> None:
    sys.stdout.write(sep.join(map(str, args)) + end)

def Solve():
    n, k = list(map(int, input().split()))
    a = list(map(int, input().split()))
    ans = 0 ; z = 0
    for i in a:
        if k>0:
            if i<0:
                ans+=-i
                k-=1
                z = i
            elif i==0: k = 0
            else:
                k = k%2
                if abs(z)<abs(i): ans+=-i
                else:
                    ans+=i
                    ans-=2*z
        else:
            ans+=i
    print(ans)


if __name__ == "__main__":
    Solve()