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

def ints_input():
    return [int(i) for i in sys.stdin.readline().strip("\n").split(" ")]

def print_list(arr):
    sys.stdout.writelines(str(x)+" " for x in arr)
    sys.stdout.write("\n")

def fast_input(type=str):
    return type(sys.stdin.readline().strip("\n"))   

n, k = ints_input()
arr = ints_input()
neg = [x for x in arr if x < 0]
if k > len(neg):
    k = k%len(neg)

arr.sort(reverse=True, key=lambda x : abs(x))

ans=0
for i in arr:
    if i < 0 and k != 0:
        ans -= i
        k-=1
    else:
        ans += i
    
print(ans)