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.
num = input();
a = num.split(" ");
l = a[0];
ch = int(a[1]);
arr_str = input();
arr = arr_str.split(" ");
buf = 0;
for i in range(len(arr)):
    if (int(arr[i]) < 0 and ch>0):
        arr[i] = str(int(arr[i]) * (-1));
        ch = ch - 1;
    else:
        buf = i;
        break;

if ch % 2 != 0:
    if int(arr[buf]) < int(arr[buf-1]):
        arr[buf] = str(int(arr[buf]) * (-1));
    elif (int(arr[buf]) > int(arr[buf -1])):
        arr[buf - 1] = str(int(arr[buf - 1]) * (-1));
    else:
        arr[buf] = str(int(arr[buf]) * (-1));
summ = 0;
for i in arr:
    summ = summ + int(i);
print(summ);

