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.
def maximum_possible_sum(nums, k):
    n = len(nums)
    pos, neg = [], []
    zero = False
    for x in nums:
        if x < 0:
            neg.append(x)
        elif x > 0:
            pos.append(x)
        else:
            zero = True
            
    neg.sort()
    
    while k > 0 and len(neg) > 0:
        pos.append(-neg[-1])
        neg.pop()
        k -= 1
           
    pos.sort()
    if k > 0:
        if zero:
            return sum(pos) + sum(neg)
        
        if k % 2 == 0:
            return sum(pos)
        else:
            return sum(pos) - pos[0] * 2
        
    else:
        return sum(pos) + sum(neg)
    
      
#t = int(input())
t = 1
for _ in range(t):
    a = list(map(int,input().split()))
    n, k = a[0], a[1]
    nums = list(map(int,input().split()))
    print(maximum_possible_sum(nums, k))
    
