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 = input()
n2=int(n[n.find(" ")+1:])
n = int(n[:n.find(" ")])
ch = input()
l2=[]
l=[]
l2 = ch.split(" ")
for i in range(len(l2)):
    l.append(int(l2[i]))
k=0
m=0
while (n2!=0):
    if k<n and m==0:
        l[k]=-l[k]
        k+=1
        if k==n:
            m==1
    if m==1 and k>0:
        l[k]=l-[k]
        k-=1
        if (k==0):
            m=0
    n2-=1
print(sum(l))