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())
s=list(map(int,input().split()))
i=0
"""
while k>0 and i<n:
    if s[i]==0:
        i+=1
        print(1)
    elif k-2>0 and s[i]>0:
        i+=1
        k-=2
        print(2)
    elif k-2<=0 and s[i]>0:
        s[i]=s[i]*(-1)
        i+=1
        k-=1
        print(3)
    elif s[i]<0:
        s[i]=s[i]*(-1)
        i+=1
        k-=1
        print(4)
    else:
        i+=1

print(s)
print(sum(s))
"""
while s[i]<0:
    s[i]=s[i]*(-1)
    i+=1
    if i==k:
        break
#print(i)
#print(s)
if i==k or s[i]==0:
    #print(s)

    
    print(sum(s))
else:
    p=k-i
    if p%2==0:
        #print(s)
        print(sum(s))

    else:
        if s[i-1]<=s[i]:
            s[i-1]=s[i-1]*(-1)
            #print(s)
            print(sum(s))
            
        else:
            s[i]=s[i]*(-1)
            #print(s)
            print(sum(s))
            
    
