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=map(int,input().split())
a=list(map(int,input().split()))
sum=0
z=0
x=-1
for i in range(n):
    if k>0 and a[i]<0:
        sum+=(a[i]*-1)
        k-=1
        x=i
    else: sum+=a[i]
    if a[i]==0: z=1

if x==-1: sum-=(a[0]*2)
elif k%2==1 and z!=1:
    if x==(n-1): sum-=(a[x]*-2)
    else:
        if (a[x]*-1)<a[x+1]: sum-=(a[x]*-2)
        else: sum-=(a[x+1]*2)
print(sum)