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.
a,b=[int(i) for i in input().split()]
c=[int(i) for i in input().split()]
sums=0
count=0
l=[]
l1=[]
for i in range(0,len(c)):
    if(c[i]<0):
        l.append(c[i])
        count=count+1
    else:
        l1.append(c[i])
        sums=sums+c[i]       
if(count==0):
    s=sorted(c)
    if(b%2==0):
        pass
    else:
        s[0]=s[0]*(-1)
    print(sum(s))    
else:
    if(count==b ):
        s=sorted(c)
        for i in range(0,count):
            s[i]=s[i]*(-1)
        print(sum(s))    
    elif(b<count):
        s=sorted(c)
        for i in range(0,b):
            s[i]=s[i]*(-1)
        print(sum(s))    
    else:
        g=b-count
        for i in range(0,len(l)):
            l[i]=l[i]*(-1)
        v=l+l1
        z=sorted(v)
        if(g%2==0):
            pass
        else:
            z[0]=(z[0]*((-1)**(b-count)))
        print(sum(z))    
            
            
