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())
l=list(map(int,input().split()))
l.sort()
sum1=0
l1=[]
e=0
for i in range(n):
    if(l[i]<0 and k>0):
        sum1=sum1+abs(l[i])
        e=max(e,i)
        k=k-1
    elif(l[i]<0 and k==0):
        sum1=sum1+l[i]
    elif(l[i]>=0 and k>0 and k%2==0):
        sum1=sum1+l[i]
        k=0
    elif(l[i]>=0 and k>0 and k%2!=0):
        if(abs(l[e])>l[i]):
            sum1=sum1-l[i]
            k=0
        elif(abs(l[e])==l[i]):
            sum1=sum1-l[i]
            k=0
        else:
            sum1=sum1-(2*abs(l[e]))
            sum1=sum1+l[i]
            k=0
    elif(k==0):
        sum1=sum1+l[i]
if(k>0 and k%2!=0):
    sum1=sum1-(2*abs(l[e]))
print(sum1)