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.





n,k = [int(x) for x in input().split()]

arr = [int(x) for x in input().split()]
# print(sum(arr))
m = 0
if(arr[n-1] >= 0):
    for i in range(n):
        if arr[i] >=0 and arr[i-1] < 0:
            m = i-1
            break
else:
    m = n-1
if m>0:
    arr[:m+1] = arr[m::-1]
if k <= m :
    arr[m-k+1:m+1] = [-x for x in arr[m-k+1:m+1]]

else:
    arr[:m+1] = [-x for x in arr[:m+1]]
    k -= m
    arr[0] *= ((-1)**(k%2+1))
# print(arr)
print(sum(arr))
