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.

Input

The first line contains two integers n and k (1 ≤ n, k ≤ 105), 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 ai (|ai| ≤ 104).

The numbers in the lines are separated by single spaces. Please note that the given sequence is sorted in non-decreasing order.

Output

In the single line print the answer to the problem — the maximum total income that we can obtain after exactly k changes.

Examples

Input

3 2
-1 -1 1


Output

3


Input

3 1
-1 -1 1


Output

1

Note

In the first sample we can get sequence [1, 1, 1], thus the total income equals 3.

In the second test, the optimal strategy is to get sequence [-1, 1, 1], thus the total income equals 1.
'''
Created on Jan 14, 2013

@author: orhan
'''

line = raw_input()
tokens = line.split(' ')
n = int(tokens[0])
k = int(tokens[1])

arr = [0] * n
line = raw_input()
tokens = line.split(' ')

for i in range(0, n):
    arr[i] = int(tokens[i])
    
index = 0

while index < k and index < n and arr[index] < 0:
    arr[index] = -arr[index]
    index += 1
    
arr.sort()

while index < k:
    arr[0] = -arr[0]
    index += 1
    
print sum(arr)