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 heapq


def solver():
    n, k = map(int, input().split())
    arr = [int(x) for x in input().split()]
    neg_arr = []
    pos_arr = []
    for e in (arr):
        if e <= 0:
            neg_arr.append(e)
        else:
            pos_arr.append(e)

    if len(neg_arr)==0:
        max_sum = sum(pos_arr[1:])+((-1)**k)*pos_arr[0]
        print(max_sum)
        return

    l = len(neg_arr)
    if l<=k:
        remaind = k-l
        max_sum = sum(pos_arr)
        max_sum+=-sum(neg_arr[:-1])
        max_sum+=neg_arr[-1]*(-1**(k-l))
        print(max_sum)
        return

    if l>k:
        max_sum = sum(pos_arr)
        for e in arr:
            if k>0:
                k-=1
                max_sum+=-e
            else:
                max_sum+=e
        print(max_sum)
        return





if __name__ == '__main__':
    solver()
