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.
#B. Roma and Changing Signs
n,k = map(int,input().split())
a = list(map(int,input().split()))
if a[0]>0:
    # we need to toggle this one on and off
    if k%2==0:
        print(sum(a))
    else:
        a[0] = -1*a[0]
        print(sum(a))
else:
    #finding first pos number
    i = 0
    while a[i]<0:
        i+=1
    if i>=k:
        while k>0:
            a[i-1] = abs(a[i-1])
            i -= 1 
            k -= 1
        print(sum(a))
    else:
        t = i
        i -= 1
        while i>=0:
            a[i] = -a[i]
            i -= 1
            k -= 1
        #toggle a[t]
        if k%2==0:
            print(sum(a))
        else:
            a[t] = -a[t]
            print(sum(a))